Deforming real-world object using an external mesh

ABSTRACT

Methods and systems are disclosed for performing operations comprising: receiving a video that includes a depiction of a real-world object; generating a three-dimensional (3D) body mesh associated with the real-world object that tracks movement of the real-world object across frames of the video; determining UV positions of the real-world object depicted in the video to obtain pixel values associated with the UV positions; generating an external mesh and associated augmented reality (AR) element representing the real-world object based on the pixel values associated with the UV positions; deforming the external mesh based on changes to the 3D body mesh and a deformation parameter; and modifying the video to replace the real-world object with the AR element based on the deformed external mesh.

TECHNICAL FIELD

The present disclosure relates generally to providing augmented realityexperiences using a messaging application.

BACKGROUND

Augmented Reality (AR) is a modification of a virtual environment. Forexample, in Virtual Reality (VR), a user is completely immersed in avirtual world, whereas in AR, the user is immersed in a world wherevirtual objects are combined or superimposed on the real world. An ARsystem aims to generate and present virtual objects that interactrealistically with a real-world environment and with each other.Examples of AR applications can include single or multiple player videogames, instant messaging systems, and the like.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. To easily identifythe discussion of any particular element or act, the most significantdigit or digits in a reference number refer to the figure number inwhich that element is first introduced. Some nonlimiting examples areillustrated in the figures of the accompanying drawings in which:

FIG. 1 is a diagrammatic representation of a networked environment inwhich the present disclosure may be deployed, in accordance with someexamples.

FIG. 2 is a diagrammatic representation of a messaging clientapplication, in accordance with some examples.

FIG. 3 is a diagrammatic representation of a data structure asmaintained in a database, in accordance with some examples.

FIG. 4 is a diagrammatic representation of a message, in accordance withsome examples.

FIG. 5 is a block diagram showing an example external mesh deformationsystem, according to example examples.

FIGS. 6, 7, and 8 are diagrammatic representations of outputs of theexternal mesh deformation system, in accordance with some examples.

FIG. 9 is a flowchart illustrating example operations of the externalmesh deformation system, according to some examples.

FIG. 10 is a diagrammatic representation of a machine in the form of acomputer system within which a set of instructions may be executed forcausing the machine to perform any one or more of the methodologiesdiscussed herein, in accordance with some examples.

FIG. 11 is a block diagram showing a software architecture within whichexamples may be implemented.

DETAILED DESCRIPTION

The description that follows includes systems, methods, techniques,instruction sequences, and computing machine program products thatembody illustrative examples of the disclosure. In the followingdescription, for the purposes of explanation, numerous specific detailsare set forth in order to provide an understanding of various examples.It will be evident, however, to those skilled in the art, that examplesmay be practiced without these specific details. In general, well-knowninstruction instances, protocols, structures, and techniques are notnecessarily shown in detail.

Typically, VR and AR systems display images representing a given user bycapturing an image of the user and, in addition, obtaining a depth mapusing a depth sensor of the real-world human body depicted in the image.By processing the depth map and the image together, the VR and ARsystems can detect positioning of a user in the image and canappropriately modify the user or background in the images. While suchsystems work well, the need for a depth sensor limits the scope of theirapplications. This is because adding depth sensors to user devices forthe purpose of modifying images increases the overall cost andcomplexity of the devices, making them less attractive.

Certain systems do away with the need to use depth sensors to modifyimages. For example, certain systems allow users to replace a backgroundin a videoconference in which a face of the user is detected.Specifically, such systems can use specialized techniques that areoptimized for recognizing a face of a user to identify the background inthe images that depict the user's face. These systems can then replaceonly those pixels that depict the background so that the real-worldbackground is replaced with an alternate background in the images.However, such systems are generally incapable of recognizing a wholebody of a user. As such, if the user is more than a threshold distancefrom the camera such that more than just the face of the user iscaptured by the camera, the replacement of the background with analternate background begins to fail. In such cases, the image quality isseverely impacted, and portions of the face and body of the user can beinadvertently removed by the system as the system falsely identifiessuch portions as belonging to the background rather than the foregroundof the images. Also, such systems fail to properly replace thebackground when more than one user is depicted in the image or videofeed. Because such systems are generally incapable of distinguishing awhole body of a user in an image from a background, these systems arealso unable to apply visual effects to certain portions of a user'sbody, such as converting, blending, transforming, changing or morphing abody part (e.g., a face) into an AR graphic.

Some AR systems allow AR graphics or AR elements to be added to an imageor video to provide engaging AR experiences. Such systems can receivethe AR graphics from a designer and can scale and position the ARgraphics within the image or video. In order to improve the placementand positioning of the AR graphics on a person depicted in the image orvideo, such systems detect a person depicted in the image or video andgenerate a rig representing bones of the person. This rig is then usedto adjust the AR graphics based on changes in movement to the rig. Whilesuch approaches generally work well, the need for generating a rig of aperson in real time to adjust AR graphics placement increases processingcomplexities and power and memory requirements. This makes such systemsinefficient or incapable of running on small scale mobile deviceswithout sacrificing computing resources or processing speed. Also, therig only represents movement of skeletal or bone structures of a personin the image or video and does not take into account any sort ofexternal physical properties of the person, such as density, weight,skin attributes, and so forth. As such, any AR graphics in these systemscan be adjusted in scale and positioning but cannot be deformed based onother physical properties of the person. In addition, an AR graphicsdesigner typically needs to create a compatible rig for their ARgraphic.

The disclosed techniques improve the efficiency of using the electronicdevice by generating a body mesh of an object, such as a person,depicted in the image and deforming an external mesh (generated based onthe person depicted in the image) in correspondence with the body mesh.By deforming an external mesh based on changes to the body mesh of adepicted object, the disclosed techniques can apply one or more visualeffects to the image or video in association with the person depicted inthe image or video in a more efficient manner and without the need forgenerating a rig or bone structure of the depicted object. Particularly,the disclosed techniques can morph, transform, change, or blend one ormore body parts of a person depicted in the image or video into one ormore AR elements taking into account movement and pose information ofthe person as determined by changes to the body mesh of the person.

This simplifies the process of adding AR graphics to an image or video,which significantly reduces design constraints and costs in generatingsuch AR graphics and decreases the amount of processing complexities andpower and memory requirements. This also improves the illusion of the ARgraphics being part of a real-world environment depicted in an image orvideo that depicts the object. This enables seamless and efficientaddition of AR graphics to an underlying image or video in real time onsmall scale mobile devices. The disclosed techniques can be appliedexclusively or mostly on a mobile device without the need for the mobiledevice to send images/videos to a server. In other examples, thedisclosed techniques are applied exclusively or mostly on a remoteserver or can be divided between a mobile device and a server.

Also, the disclosed techniques allow an AR graphics designer to generatean external mesh for their AR graphics without creating a compatible rigfor the AR graphics which saves time, effort, and creation complexity.The disclosed techniques enable the AR graphics (AR fashion items) to bedeformed with the user's shape (weight, height, body shape, and soforth) by creating a correspondence between a body mesh and an externalmesh of an AR graphic or AR fashion item. The disclosed techniques alsoenable certain portions of a real-world object to be blended or morphedinto the AR graphics using correspondence information between theexternal mesh and body mesh and based on movement information associatedwith the body mesh.

As a result, a realistic display can be provided that shows the userbeing morphed into an AR graphic while moving around a video in threedimensions (3D), including changes to the body shape, body state, bodyproperties, position, and rotation, in a way that is intuitive for theuser to interact with and select. As used herein, “article of clothing,”“fashion item,” and “garment” are used interchangeably and should beunderstood to have the same meaning. This improves the overallexperience of the user in using the electronic device. Also, byproviding such AR experiences without using a depth sensor, the overallamount of system resources needed to accomplish a task is reduced.

Networked Computing Environment

FIG. 1 is a block diagram showing an example messaging system 100 forexchanging data (e.g., messages and associated content) over a network.The messaging system 100 includes multiple instances of a client device102, each of which hosts a number of applications, including a messagingclient 104 and other external applications 109 (e.g., third-partyapplications). Each messaging client 104 is communicatively coupled toother instances of the messaging client 104 (e.g., hosted on respectiveother client devices 102), a messaging server system 108, and externalapp(s) servers 110 via a network 112 (e.g., the Internet). A messagingclient 104 can also communicate with locally-hosted third-partyapplications, such as external apps 109 using Application ProgrammingInterfaces (APIs).

A messaging client 104 is able to communicate and exchange data withother messaging clients 104 and with the messaging server system 108 viathe network 112. The data exchanged between messaging clients 104, andbetween a messaging client 104 and the messaging server system 108,includes functions (e.g., commands to invoke functions) as well aspayload data (e.g., text, audio, video, or other multimedia data).

The messaging server system 108 provides server-side functionality viathe network 112 to a particular messaging client 104. While certainfunctions of the messaging system 100 are described herein as beingperformed by either a messaging client 104 or by the messaging serversystem 108, the location of certain functionality either within themessaging client 104 or the messaging server system 108 may be a designchoice. For example, it may be technically preferable to initiallydeploy certain technology and functionality within the messaging serversystem 108 but to later migrate this technology and functionality to themessaging client 104 where a client device 102 has sufficient processingcapacity.

The messaging server system 108 supports various services and operationsthat are provided to the messaging client 104. Such operations includetransmitting data to, receiving data from, and processing data generatedby the messaging client 104. This data may include message content,client device information, geolocation information, media augmentationand overlays, message content persistence conditions, social networkinformation, and live event information, as examples. Data exchangeswithin the messaging system 100 are invoked and controlled throughfunctions available via user interfaces of the messaging client 104.

Turning now specifically to the messaging server system 108, an APIserver 116 is coupled to, and provides a programmatic interface to,application servers 114. The application servers 114 are communicativelycoupled to a database server 120, which facilitates access to a database126 that stores data associated with messages processed by theapplication servers 114. Similarly, a web server 128 is coupled to theapplication servers 114 and provides web-based interfaces to theapplication servers 114. To this end, the web server 128 processesincoming network requests over the Hypertext Transfer Protocol (HTTP)and several other related protocols.

The API server 116 receives and transmits message data (e.g., commandsand message payloads) between the client device 102 and the applicationservers 114. Specifically, the API server 116 provides a set ofinterfaces (e.g., routines and protocols) that can be called or queriedby the messaging client 104 in order to invoke functionality of theapplication servers 114. The API server 116 exposes various functionssupported by the application servers 114, including accountregistration; login functionality; the sending of messages, via theapplication servers 114, from a particular messaging client 104 toanother messaging client 104; the sending of media files (e.g., imagesor video) from a messaging client 104 to a messaging server 118, and forpossible access by another messaging client 104; the settings of acollection of media data (e.g., story); the retrieval of a list offriends of a user of a client device 102; the retrieval of suchcollections; the retrieval of messages and content; the addition anddeletion of entities (e.g., friends) to an entity graph (e.g., a socialgraph); the location of friends within a social graph; and opening anapplication event (e.g., relating to the messaging client 104).

The application servers 114 host a number of server applications andsubsystems, including, for example, a messaging server 118, an imageprocessing server 122, and a social network server 124. The messagingserver 118 implements a number of message processing technologies andfunctions, particularly related to the aggregation and other processingof content (e.g., textual and multimedia content) included in messagesreceived from multiple instances of the messaging client 104. As will bedescribed in further detail, the text and media content from multiplesources may be aggregated into collections of content (e.g., calledstories or galleries). These collections are then made available to themessaging client 104. Other processor- and memory-intensive processingof data may also be performed server-side by the messaging server 118,in view of the hardware requirements for such processing.

The application servers 114 also include an image processing server 122that is dedicated to performing various image processing operations,typically with respect to images or video within the payload of amessage sent from or received at the messaging server 118.

Image processing server 122 is used to implement scan functionality ofthe augmentation system 208 (shown in FIG. 2 ). Scan functionalityincludes activating and providing one or more AR experiences on a clientdevice 102 when an image is captured by the client device 102.Specifically, the messaging client 104 on the client device 102 can beused to activate a camera. The camera displays one or more real-timeimages or a video to a user along with one or more icons or identifiersof one or more AR experiences. The user can select a given one of theidentifiers to launch the corresponding AR experience or perform adesired image modification (e.g., replacing a garment being worn by auser in a video or morph, change, blend or transform a portion of a bodyof a person or user into an AR graphic, such as an AR werewolf or ARbat).

The social network server 124 supports various social networkingfunctions and services and makes these functions and services availableto the messaging server 118. To this end, the social network server 124maintains and accesses an entity graph 308 (as shown in FIG. 3 ) withinthe database 126. Examples of functions and services supported by thesocial network server 124 include the identification of other users ofthe messaging system 100 with which a particular user has relationshipsor is “following,” and also the identification of other entities andinterests of a particular user.

Returning to the messaging client 104, features and functions of anexternal resource (e.g., a third-party application 109 or applet) aremade available to a user via an interface of the messaging client 104.The messaging client 104 receives a user selection of an option tolaunch or access features of an external resource (e.g., a third-partyresource), such as external apps 109. The external resource may be athird-party application (external apps 109) installed on the clientdevice 102 (e.g., a “native app”) or a small-scale version of thethird-party application (e.g., an “applet”) that is hosted on the clientdevice 102 or remote of the client device 102 (e.g., on third-partyservers 110). The small-scale version of the third-party applicationincludes a subset of features and functions of the third-partyapplication (e.g., the full-scale, native version of the third-partystandalone application) and is implemented using a markup-languagedocument. In one example, the small-scale version of the third-partyapplication (e.g., an “applet”) is a web-based, markup-language versionof the third-party application and is embedded in the messaging client104. In addition to using markup-language documents (e.g., a .*ml file),an applet may incorporate a scripting language (e.g., a .*js file or a.json file) and a style sheet (e.g., a .*ss file).

In response to receiving a user selection of the option to launch oraccess features of the external resource (external app 109), themessaging client 104 determines whether the selected external resourceis a web-based external resource or a locally-installed externalapplication. In some cases, external applications 109 that are locallyinstalled on the client device 102 can be launched independently of andseparately from the messaging client 104, such as by selecting an icon,corresponding to the external application 109, on a home screen of theclient device 102. Small-scale versions of such external applicationscan be launched or accessed via the messaging client 104 and, in someexamples, no or limited portions of the small-scale external applicationcan be accessed outside of the messaging client 104. The small-scaleexternal application can be launched by the messaging client 104receiving, from an external app(s) server 110, a markup-languagedocument associated with the small-scale external application andprocessing such a document.

In response to determining that the external resource is alocally-installed external application 109, the messaging client 104instructs the client device 102 to launch the external application 109by executing locally-stored code corresponding to the externalapplication 109. In response to determining that the external resourceis a web-based resource, the messaging client 104 communicates with theexternal app(s) servers 110 to obtain a markup-language documentcorresponding to the selected resource. The messaging client 104 thenprocesses the obtained markup-language document to present the web-basedexternal resource within a user interface of the messaging client 104.

The messaging client 104 can notify a user of the client device 102, orother users related to such a user (e.g., “friends”), of activity takingplace in one or more external resources. For example, the messagingclient 104 can provide participants in a conversation (e.g., a chatsession) in the messaging client 104 with notifications relating to thecurrent or recent use of an external resource by one or more members ofa group of users. One or more users can be invited to join in an activeexternal resource or to launch a recently-used but currently inactive(in the group of friends) external resource. The external resource canprovide participants in a conversation, each using a respectivemessaging client 104, with the ability to share an item, status, state,or location in an external resource with one or more members of a groupof users into a chat session. The shared item may be an interactive chatcard with which members of the chat can interact, for example, to launchthe corresponding external resource, view specific information withinthe external resource, or take the member of the chat to a specificlocation or state within the external resource. Within a given externalresource, response messages can be sent to users on the messaging client104. The external resource can selectively include different media itemsin the responses, based on a current context of the external resource.

The messaging client 104 can present a list of the available externalresources (e.g., third-party or external applications 109 or applets) toa user to launch or access a given external resource. This list can bepresented in a context-sensitive menu. For example, the iconsrepresenting different ones of the external application 109 (or applets)can vary based on how the menu is launched by the user (e.g., from aconversation interface or from a non-conversation interface).

The messaging client 104 can present to a user one or more ARexperiences. As an example, the messaging client 104 can detect a personor user in an image or video captured by the client device 102. Themessaging client 104 can generate a body mesh for the person depicted inthe image or video. The body mesh can be a 3D mesh, or polygon mesh,that includes a collection of vertices, edges, and faces that define theshape of a polyhedral object depicted in the image or video. The meshcan be a collection of several closed surfaces. In a mathematical vectoralgebraic sense, which may be important for calculations, a mesh can bea collection of numbers organized into several matrices. In a geometricdescription, a mesh can be made of points that are joined together withsegments and surfaced by polygons.

The messaging client 104 can receive a user selection of an ARexperience (e.g., a deformation parameter) to modify the 3D mesh of theperson or user depicted in the image, such as to modify (enlarge,expand, shrink, reduce, and so forth) a portion the user or person(e.g., a body part, such as a hand, head, legs, torso, or anycombination thereof). In response, the messaging client 104 can generatean external mesh based on the 3D mesh and a texture corresponding to theperson or user depicted in the image. The messaging client 104 canautomatically generate or determine a correspondence between theexternal mesh and the 3D body mesh, such as by copying positioninformation associated with the 3D body mesh into placement informationassociated with the external mesh. The messaging client 104 canautomatically adjust the placement information associated with theexternal mesh based on movement information associated with the 3D bodymesh, such that the external mesh expands, contracts, rotates, and/or isrepositioned in 3D space in a similar manner as the 3D body mesh. Themessaging client 104 can obtain a UV map representing pixels of theperson or user associated with the 3D body mesh in two-dimensional (2D)space and can use the UV map to generate the texture for the externalmesh. UV mapping is the 3D modeling process of projecting a 2D image toa 3D model's surface for texture mapping. The letters “U” and “V” denotethe axes of the 2D texture because “X”, “Y”, and “Z” are already used todenote the axes of the 3D object in model space The texture of theexternal mesh can represent visual attributes of the body of the persondepicted in the image or video, such as the same skin color, blemishes,freckles, hair, nails, wrinkles, and so forth. In this way, an ARgraphic is produced that represents the person or user depicted in theimage or video and that is moved around and repositioned as the personor user moves around the image or video.

The AR graphic can be associated with the external mesh to modifymovement of the AR graphic in 3D space. Input can be received from theuser that includes a deformation parameter to modify the AR graphic,such as to enlarge or shrink a body part represented by the AR graphic.For example, the deformation parameter can specify an amount by which toreduce a waist size of the body represented by the AR graphic. Inresponse, the messaging client 104 can shrink the portion of theexternal mesh corresponding to the waist of the body by a specifiedamount in the input received from the user. As a result, the waistportion of the AR graphic texture corresponding to the waist portion ofthe external mesh is similarly reduced or shrunk in size. The messagingclient 104 can then modify the image or video to replace the UV pixelsand/or corresponding position of the 3D body mesh with the AR graphicthat has been modified. In an example, the messaging client 104 canblend the UV pixels of the person or user depicted in the image or videointo the AR graphic according to a blending parameter, such as to slowlytransition the depiction of the person or user in the image or videointo the AR graphic representing the same person or user with a reducedwaist portion.

As another example, in addition to (or alternative to) reducing a sizeof a portion of the AR graphic, additional input can be received toincrease a size of a second portion of the AR graphic. Namely, input canbe received from the user that includes a deformation parameter tomodify the AR graphic, such as to enlarge or shrink a second body partrepresented by the AR graphic. For example, the deformation parametercan specify an amount by which to increase a length of legs of the bodyrepresented by the AR graphic. In response, the messaging client 104 canenlarge the portion of the external mesh corresponding to the legs ofthe body by a specified amount in the input received from the user. As aresult, the legs portion of the AR graphic texture corresponding to thelegs portion of the external mesh is similarly increased in size. Aspart of the process of increasing a size of a portion of the AR graphic,the messaging client 104 can determine pixel values of the AR graphiccorresponding to an edge of the portion being increased in size. Forexample, the messaging client 104 can obtain the pixel values around thetop of the legs portion of the AR graphic. The messaging client 104 canthen blend the pixel values around the top of the legs into the enlargedportion of the legs to provide continuity between the original leg sizeand the enlarged legs size. The messaging client 104 can then modify theimage or video to replace the UV pixels and/or corresponding position ofthe 3D body mesh with the AR graphic that has been modified (to havelonger legs and reduced waist size). In an example, the messaging client104 can blend the UV pixels of the person or user depicted in the imageor video into the AR graphic according to a blending parameter, such asto slowly transition the depiction of the person or user in the image orvideo into the AR graphic representing the same person or user with areduced waist portion and longer legs.

As another example, in addition to (or alternative to) reducing a sizeof a portion of the AR graphic, additional input can be received tochange a color or add a graphical element (e.g., an AR tattoo) to athird portion of the AR graphic. Namely, input can be received from theuser that includes a deformation parameter to add a graphical element orchange a color of a portion of the AR graphic, such as to change a colorof a third body part represented by the AR graphic. In response, themessaging client 104 can select the portion of the external meshcorresponding to the third portion of the AR graphic, such as the leftarm of the body. The messaging client 104 can modify the texture of thethird portion of the AR graphic to correspond to the requested new coloror to overlay the graphical element to make it appear as though a tattoohas been added to the third portion of the AR graphic. The messagingclient 104 can then modify the image or video to replace the UV pixelsand/or corresponding position of the 3D body mesh with the AR graphicthat has been modified (to have longer legs, reduced waist size, andmodified color of the left arm of the body including addition of the ARtattoo). In an example, the messaging client 104 can blend the UV pixelsof the person or user depicted in the image or video into the AR graphicaccording to a blending parameter, such as to slowly transition thedepiction of the person or user in the image or video into the ARgraphic representing the same person or user with a reduced waistportion, longer legs, and modified left arm. While the disclosedexamples are discussed in relation to modifying a person or userdepicted in an image or video, similar techniques can be applied tomodify any other real-world object, such as an animal, furniture, abuilding, and so forth.

As mentioned above, the external mesh associated with the AR graphic caninclude a blending parameter for controlling how a real-world objectportion is morphed, blended, changed, or transformed into the modifiedAR graphic that represents the person or user depicted in the image orvideo. The blending parameter can include a linear or non-linearfunction that controls how quickly or slowly the real-world objectportion is blended into the AR graphic. The AR graphic can also includeinformation indicating which portions of the real-world object, person,or user to blend into the AR graphic and which portions to not change.For example, the AR graphic can specify that the head of the object,person, or user is to be transformed into the head of the AR graphicwithout changing or affecting other portions of the object, person, oruser (e.g., the arms, legs, hands, and torso).

The messaging client 104 can automatically establish a correspondencebetween the body mesh (e.g., 3D body mesh) and the external mesh. Themessaging client 104 can position the external mesh over or with respectto the 3D body mesh within the image or video. The messaging client 104can determine (based on placement information associated with theexternal mesh) a first portion or first set of portions of the externalmesh that are deformed based on movement information associated with the3D body mesh. For example, if the AR graphic is a head of an animal, theplacement information can specify that the head portion of the externalmesh (the portion of the external mesh corresponding to a head of theanimal or AR werewolf) is to be deformed based on movement informationassociated with the head portion of the 3D body mesh. The messagingclient 104 can then blend, transform, morph, or change the head portionof the 3D body mesh into the AR graphic according to the blendingparameter while deforming the external mesh based on movementinformation of the 3D body mesh. This allows the object, user, or persondepicted in the image or video to continue to move around while aportion of the object, user, or person is blended, morphed, transformed,or changed into the AR graphic. This provides the user with a realisticdisplay of the image or video depiction of the person combined with theselected AR graphic.

In this way, the messaging client 104 can adjust an external mesh (andas a result the AR graphic associated with the external mesh) in realtime based on movements and other changes (e.g., changes to the bodyshape, position, rotation and scale) of a body mesh associated with anobject, such as a person, depicted in the image or video and while alsoblending at least a portion of the real-world object into the AR graphicaccording to a blending parameter (e.g., a linear or non-linearfunction). This provides an illusion that the AR graphic is actuallyincluded in the real-world environment depicted in the image or video,which improves the overall user experience. Further details of thedeformation of the external mesh with respect to the body mesh andblending parameters are provided below in connection with FIG. 5 .

System Architecture

FIG. 2 is a block diagram illustrating further details regarding themessaging system 100, according to some examples. Specifically, themessaging system 100 is shown to comprise the messaging client 104 andthe application servers 114. The messaging system 100 embodies a numberof subsystems, which are supported on the client side by the messagingclient 104 and on the sever side by the application servers 114. Thesesubsystems include, for example, an ephemeral timer system 202, acollection management system 204, an augmentation system 208, a mapsystem 210, a game system 212, and an external resource system 220.

The ephemeral timer system 202 is responsible for enforcing thetemporary or time-limited access to content by the messaging client 104and the messaging server 118. The ephemeral timer system 202incorporates a number of timers that, based on duration and displayparameters associated with a message, or collection of messages (e.g., astory), selectively enable access (e.g., for presentation and display)to messages and associated content via the messaging client 104. Furtherdetails regarding the operation of the ephemeral timer system 202 areprovided below.

The collection management system 204 is responsible for managing sets orcollections of media (e.g., collections of text, image video, and audiodata). A collection of content (e.g., messages, including images, video,text, and audio) may be organized into an “event gallery” or an “eventstory.” Such a collection may be made available for a specified timeperiod, such as the duration of an event to which the content relates.For example, content relating to a music concert may be made availableas a “story” for the duration of that music concert. The collectionmanagement system 204 may also be responsible for publishing an iconthat provides notification of the existence of a particular collectionto the user interface of the messaging client 104.

The collection management system 204 further includes a curationinterface 206 that allows a collection manager to manage and curate aparticular collection of content. For example, the curation interface206 enables an event organizer to curate a collection of contentrelating to a specific event (e.g., delete inappropriate content orredundant messages). Additionally, the collection management system 204employs machine vision (or image recognition technology) and contentrules to automatically curate a content collection. In certain examples,compensation may be paid to a user for the inclusion of user-generatedcontent into a collection. In such cases, the collection managementsystem 204 operates to automatically make payments to such users for theuse of their content.

The augmentation system 208 provides various functions that enable auser to augment (e.g., annotate or otherwise modify or edit) mediacontent associated with a message. For example, the augmentation system208 provides functions related to the generation and publishing of mediaoverlays for messages processed by the messaging system 100. Theaugmentation system 208 operatively supplies a media overlay oraugmentation (e.g., an image filter) to the messaging client 104 basedon a geolocation of the client device 102. In another example, theaugmentation system 208 operatively supplies a media overlay to themessaging client 104 based on other information, such as social networkinformation of the user of the client device 102. A media overlay mayinclude audio and visual content and visual effects. Examples of audioand visual content include pictures, texts, logos, animations, and soundeffects. An example of a visual effect includes color overlaying. Theaudio and visual content or the visual effects can be applied to a mediacontent item (e.g., a photo) at the client device 102. For example, themedia overlay may include text, a graphical element, or image that canbe overlaid on top of a photograph taken by the client device 102. Inanother example, the media overlay includes an identification of alocation overlay (e.g., Venice beach), a name of a live event, or a nameof a merchant overlay (e.g., Beach Coffee House). In another example,the augmentation system 208 uses the geolocation of the client device102 to identify a media overlay that includes the name of a merchant atthe geolocation of the client device 102. The media overlay may includeother indicia associated with the merchant. The media overlays may bestored in the database 126 and accessed through the database server 120.

In some examples, the augmentation system 208 provides a user-basedpublication platform that enables users to select a geolocation on a mapand upload content associated with the selected geolocation. The usermay also specify circumstances under which a particular media overlayshould be offered to other users. The augmentation system 208 generatesa media overlay that includes the uploaded content and associates theuploaded content with the selected geolocation.

In other examples, the augmentation system 208 provides a merchant-basedpublication platform that enables merchants to select a particular mediaoverlay associated with a geolocation via a bidding process. Forexample, the augmentation system 208 associates the media overlay of thehighest bidding merchant with a corresponding geolocation for apredefined amount of time. The augmentation system 208 communicates withthe image processing server 122 to obtain augmented reality experiencesand presents identifiers of such experiences in one or more userinterfaces (e.g., as icons over a real-time image or video or asthumbnails or icons in interfaces dedicated for presented identifiers ofaugmented reality experiences). Once an AR experience is selected, oneor more images, videos, or AR graphical elements are retrieved andpresented as an overlay on top of the images or video captured by theclient device 102. In some cases, the camera is switched to afront-facing view (e.g., the front-facing camera of the client device102 is activated in response to activation of a particular ARexperience) and the images from the front-facing camera of the clientdevice 102 start being displayed on the client device 102 instead of therear-facing camera of the client device 102. The one or more images,videos, or AR graphical elements are retrieved and presented as anoverlay on top of the images that are captured and displayed by thefront-facing camera of the client device 102.

In other examples, the augmentation system 208 is able to communicateand exchange data with another augmentation system 208 on another clientdevice 102 and with the server via the network 112. The data exchangedcan include a session identifier that identifies the shared AR session,a transformation between a first client device 102 and a second clientdevice 102 (e.g., a plurality of client devices 102 including the firstand second devices) that is used to align the shared AR session to acommon point of origin, a common coordinate frame, and functions (e.g.,commands to invoke functions) as well as other payload data (e.g., text,audio, video, or other multimedia data).

The augmentation system 208 sends the transformation to the secondclient device 102 so that the second client device 102 can adjust the ARcoordinate system based on the transformation. In this way, the firstand second client devices 102 synch up their coordinate systems andframes for displaying content in the AR session. Specifically, theaugmentation system 208 computes the point of origin of the secondclient device 102 in the coordinate system of the first client device102. The augmentation system 208 can then determine an offset in thecoordinate system of the second client device 102 based on the positionof the point of origin from the perspective of the second client device102 in the coordinate system of the second client device 102. Thisoffset is used to generate the transformation so that the second clientdevice 102 generates AR content according to a common coordinate systemor frame as the first client device 102.

The augmentation system 208 can communicate with the client device 102to establish individual or shared AR sessions. The augmentation system208 can also be coupled to the messaging server 118 to establish anelectronic group communication session (e.g., group chat, instantmessaging) for the client devices 102 in a shared AR session. Theelectronic group communication session can be associated with a sessionidentifier provided by the client devices 102 to gain access to theelectronic group communication session and to the shared AR session. Inone example, the client devices 102 first gain access to the electronicgroup communication session and then obtain the session identifier inthe electronic group communication session that allows the clientdevices 102 to access the shared AR session. In some examples, theclient devices 102 are able to access the shared AR session without aidor communication with the augmentation system 208 in the applicationservers 114.

The map system 210 provides various geographic location functions andsupports the presentation of map-based media content and messages by themessaging client 104. For example, the map system 210 enables thedisplay of user icons or avatars (e.g., stored in profile data 316) on amap to indicate a current or past location of “friends” of a user, aswell as media content (e.g., collections of messages includingphotographs and videos) generated by such friends, within the context ofa map. For example, a message posted by a user to the messaging system100 from a specific geographic location may be displayed within thecontext of a map at that particular location to “friends” of a specificuser on a map interface of the messaging client 104. A user canfurthermore share his or her location and status information (e.g.,using an appropriate status avatar) with other users of the messagingsystem 100 via the messaging client 104, with this location and statusinformation being similarly displayed within the context of a mapinterface of the messaging client 104 to selected users.

The game system 212 provides various gaming functions within the contextof the messaging client 104. The messaging client 104 provides a gameinterface providing a list of available games (e.g., web-based games orweb-based applications) that can be launched by a user within thecontext of the messaging client 104 and played with other users of themessaging system 100. The messaging system 100 further enables aparticular user to invite other users to participate in the play of aspecific game by issuing invitations to such other users from themessaging client 104. The messaging client 104 also supports both voiceand text messaging (e.g., chats) within the context of gameplay,provides a leaderboard for the games, and also supports the provision ofin-game rewards (e.g., coins and items).

The external resource system 220 provides an interface for the messagingclient 104 to communicate with external app(s) servers 110 to launch oraccess external resources. Each external resource (apps) server 110hosts, for example, a markup language (e.g., HTML5) based application orsmall-scale version of an external application (e.g., game, utility,payment, or ride-sharing application that is external to the messagingclient 104). The messaging client 104 may launch a web-based resource(e.g., application) by accessing the HTML5 file from the externalresource (apps) servers 110 associated with the web-based resource. Incertain examples, applications hosted by external resource servers 110are programmed in JavaScript leveraging a Software Development Kit (SDK)provided by the messaging server 118. The SDK includes APIs withfunctions that can be called or invoked by the web-based application. Incertain examples, the messaging server 118 includes a JavaScript librarythat provides a given third-party resource access to certain user dataof the messaging client 104. HTML5 is used as an example technology forprogramming games, but applications and resources programmed based onother technologies can be used.

In order to integrate the functions of the SDK into the web-basedresource, the SDK is downloaded by an external resource (apps) server110 from the messaging server 118 or is otherwise received by theexternal resource (apps) server 110. Once downloaded or received, theSDK is included as part of the application code of a web-based externalresource. The code of the web-based resource can then call or invokecertain functions of the SDK to integrate features of the messagingclient 104 into the web-based resource.

The SDK stored on the messaging server 118 effectively provides thebridge between an external resource (e.g., third-party or externalapplications 109 or applets and the messaging client 104). This providesthe user with a seamless experience of communicating with other users onthe messaging client 104, while also preserving the look and feel of themessaging client 104. To bridge communications between an externalresource and a messaging client 104, in certain examples, the SDKfacilitates communication between external resource servers 110 and themessaging client 104. In certain examples, a WebViewJavaScriptBridgerunning on a client device 102 establishes two one-way communicationchannels between an external resource and the messaging client 104.Messages are sent between the external resource and the messaging client104 via these communication channels asynchronously. Each SDK functioninvocation is sent as a message and callback. Each SDK function isimplemented by constructing a unique callback identifier and sending amessage with that callback identifier.

By using the SDK, not all information from the messaging client 104 isshared with external resource servers 110. The SDK limits whichinformation is shared based on the needs of the external resource. Incertain examples, each external resource server 110 provides an HTML5file corresponding to the web-based external resource to the messagingserver 118. The messaging server 118 can add a visual representation(such as a box art or other graphic) of the web-based external resourcein the messaging client 104. Once the user selects the visualrepresentation or instructs the messaging client 104 through a GUI ofthe messaging client 104 to access features of the web-based externalresource, the messaging client 104 obtains the HTML5 file andinstantiates the resources necessary to access the features of theweb-based external resource.

The messaging client 104 presents a graphical user interface (e.g., alanding page or title screen) for an external resource. During, before,or after presenting the landing page or title screen, the messagingclient 104 determines whether the launched external resource has beenpreviously authorized to access user data of the messaging client 104.In response to determining that the launched external resource has beenpreviously authorized to access user data of the messaging client 104,the messaging client 104 presents another graphical user interface ofthe external resource that includes functions and features of theexternal resource. In response to determining that the launched externalresource has not been previously authorized to access user data of themessaging client 104, after a threshold period of time (e.g., 3 seconds)of displaying the landing page or title screen of the external resource,the messaging client 104 slides up (e.g., animates a menu as surfacingfrom a bottom of the screen to a middle of or other portion of thescreen) a menu for authorizing the external resource to access the userdata. The menu identifies the type of user data that the externalresource will be authorized to use. In response to receiving a userselection of an accept option, the messaging client 104 adds theexternal resource to a list of authorized external resources and allowsthe external resource to access user data from the messaging client 104.In some examples, the external resource is authorized by the messagingclient 104 to access the user data in accordance with an OAuth 2framework.

The messaging client 104 controls the type of user data that is sharedwith external resources based on the type of external resource beingauthorized. For example, external resources that include full-scaleexternal applications (e.g., a third-party or external application 109)are provided with access to a first type of user data (e.g., only 2Davatars of users with or without different avatar characteristics). Asanother example, external resources that include small-scale versions ofexternal applications (e.g., web-based versions of third-partyapplications) are provided with access to a second type of user data(e.g., payment information, 2D avatars of users, 3D avatars of users,and avatars with various avatar characteristics). Avatar characteristicsinclude different ways to customize a look and feel of an avatar, suchas different poses, facial features, clothing, and so forth.

An external mesh deformation system 224 deforms an external mesh basedon changes to a 3D body mesh of a real-world object depicted in an imageor video in real time and morphs, changes, transforms, or blends atleast a portion of the real-world object into the AR graphic representedby the external mesh. In an example, the external mesh deformationsystem 224 can receive a selection of a deformation parameter associatedwith an AR graphic, such as an indication to reduce a waist size of theAR graphic, extend legs of the AR graphic, and/or change a color or adda graphical element to an arm of the AR graphic. The external meshdeformation system 224 identifies a body part of the real-world objectdepicted in the image or video that corresponds to the AR graphic, suchas based on placement information associated with the AR graphic. Theexternal mesh deformation system 224 deforms the external meshcorresponding to the AR graphic based on movement information associatedwith the 3D body mesh. The external mesh deformation system 224 obtainsa blending parameter and changes, blends, deforms, transforms, or morphsat least the body part of the 3D body mesh of the real-world object intothe external mesh while continuing to update and deform the externalmesh based on movement information associated with the 3D body mesh.

In one example, the external mesh deformation system 224 changes,blends, deforms, transforms, or morphs at least the body part of the 3Dbody mesh of the real-world object into the external mesh linearly overa given time interval, such that updates to the 3D body mesh are beingmade repeatedly at equally spaced time points. In another example, theexternal mesh deformation system 224 changes, blends, deforms,transforms, or morphs at least the 3D body mesh of the body part of thereal-world object into the external mesh non-linearly over a given timeinterval, such that a first set of updates to the real-world body partof the 3D body mesh are being made at a first rate, such as repeatedlyat equally spaced time points to create a partially blended 3D bodymesh. Subsequently, the first rate is modified (increased or decreased)so that a second set of updates to the partially blended real-world 3Dbody mesh continue to be made at a faster or slower pace until thereal-world body part of the 3D body mesh is completely transformed intothe external mesh (e.g., into the AR graphic). As a result, the externalmesh deformation system 224 continuously or periodically represents anddepicts changes to the body part in the image or video to represent thebody part being morphed, changed, blended, or transformed into having asmaller waist, longer legs, and modified left arm. An illustrativeimplementation of the external mesh deformation system 224 is shown anddescribed in connection with FIG. 5 below.

Specifically, the external mesh deformation system 224 is a componentthat can be accessed by an AR/VR application implemented on the clientdevice 102. The AR/VR application uses an RGB camera to capture amonocular image of a user. The AR/VR application applies various trainedmachine learning techniques on the captured image of the user togenerate a 3D body mesh representing the user depicted in the image andto apply one or more AR visual effects to the captured image bydeforming one or more external meshes associated with the AR visualeffects. In some implementations, the AR/VR application continuouslycaptures images of the user and updates the 3D body mesh and externalmesh(es) in real time or periodically to continuously or periodicallyupdate the applied one or more visual effects. This allows the user tomove around in the real world and see the one or more visual effectsupdate in real time. In some examples, the external mesh deformationsystem 224 automatically establishes a correspondence between theexternal mesh and the 3D body mesh once prior to runtime (e.g., beforethe AR graphics are presented to the user) and then the external meshand the 3D body mesh are deformed with respect to each other duringruntime to update the display of the AR graphics associated with theexternal mesh. In other examples, the automated correspondence cancontinuously be updated and generated during runtime while alsodeforming the external mesh.

In training, the external mesh deformation system 224 obtains a firstplurality of input training images that include depictions of one ormore users having different body types and characteristics. Thesetraining images also provide the ground truth information including bodymeshes corresponding to the one or more users depicted in each image. Amachine learning technique (e.g., a deep neural network) is trainedbased on features of the plurality of training images. Specifically, themachine learning technique extracts one or more features from a giventraining image and estimates a 3D body mesh for the user depicted in thegiven training image. The machine learning technique obtains the groundtruth information including the 3D body mesh corresponding to thetraining image and adjusts or updates one or more coefficients orparameters to improve subsequent estimations of body meshes.

Data Architecture

FIG. 3 is a schematic diagram illustrating data structures 300, whichmay be stored in the database 126 of the messaging server system 108,according to certain examples. While the content of the database 126 isshown to comprise a number of tables, it will be appreciated that thedata could be stored in other types of data structures (e.g., as anobject-oriented database).

The database 126 includes message data stored within a message table302. This message data includes, for any particular one message, atleast message sender data, message recipient (or receiver) data, and apayload. Further details regarding information that may be included in amessage, and included within the message data stored in the messagetable 302, are described below with reference to FIG. 4 .

An entity table 306 stores entity data, and is linked (e.g.,referentially) to an entity graph 308 and profile data 316. Entities forwhich records are maintained within the entity table 306 may includeindividuals, corporate entities, organizations, objects, places, events,and so forth. Regardless of entity type, any entity regarding which themessaging server system 108 stores data may be a recognized entity. Eachentity is provided with a unique identifier, as well as an entity typeidentifier (not shown).

The entity graph 308 stores information regarding relationships andassociations between entities. Such relationships may be social,professional (e.g., work at a common corporation or organization)interested-based, or activity-based, merely for example.

The profile data 316 stores multiple types of profile data about aparticular entity. The profile data 316 may be selectively used andpresented to other users of the messaging system 100, based on privacysettings specified by a particular entity. Where the entity is anindividual, the profile data 316 includes, for example, a user name,telephone number, address, and settings (e.g., notification and privacysettings), as well as a user-selected avatar representation (orcollection of such avatar representations). A particular user may thenselectively include one or more of these avatar representations withinthe content of messages communicated via the messaging system 100 and onmap interfaces displayed by messaging clients 104 to other users. Thecollection of avatar representations may include “status avatars,” whichpresent a graphical representation of a status or activity that the usermay select to communicate at a particular time.

Where the entity is a group, the profile data 316 for the group maysimilarly include one or more avatar representations associated with thegroup, in addition to the group name, members, and various settings(e.g., notifications) for the relevant group.

The database 126 also stores augmentation data, such as overlays orfilters, in an augmentation table 310. The augmentation data isassociated with and applied to videos (for which data is stored in avideo table 304) and images (for which data is stored in an image table312).

The database 126 can also store data pertaining to individual and sharedAR sessions. This data can include data communicated between an ARsession client controller of a first client device 102 and another ARsession client controller of a second client device 102, and datacommunicated between the AR session client controller and theaugmentation system 208. Data can include data used to establish thecommon coordinate frame of the shared AR scene, the transformationbetween the devices, the session identifier, images depicting a body,skeletal joint positions, wrist joint positions, feet, and so forth.

Filters, in one example, are overlays that are displayed as overlaid onan image or video during presentation to a recipient user. Filters maybe of various types, including user-selected filters from a set offilters presented to a sending user by the messaging client 104 when thesending user is composing a message. Other types of filters includegeolocation filters (also known as geo-filters), which may be presentedto a sending user based on geographic location. For example, geolocationfilters specific to a neighborhood or special location may be presentedwithin a user interface by the messaging client 104, based ongeolocation information determined by a Global Positioning System (GPS)unit of the client device 102.

Another type of filter is a data filter, which may be selectivelypresented to a sending user by the messaging client 104, based on otherinputs or information gathered by the client device 102 during themessage creation process. Examples of data filters include currenttemperature at a specific location, a current speed at which a sendinguser is traveling, battery life for a client device 102, or the currenttime.

Other augmentation data that may be stored within the image table 312includes AR content items (e.g., corresponding to applying augmentedreality experiences). An AR content item or AR item may be a real-timespecial effect and sound that may be added to an image or a video.

As described above, augmentation data includes AR content items,overlays, image transformations, AR images, AR logos or emblems, andsimilar terms that refer to modifications that may be applied to imagedata (e.g., videos or images). This includes real-time modifications,which modify an image as it is captured using device sensors (e.g., oneor multiple cameras) of a client device 102 and then displayed on ascreen of the client device 102 with the modifications. This alsoincludes modifications to stored content, such as video clips in agallery that may be modified. For example, in a client device 102 withaccess to multiple AR content items, a user can use a single video clipwith multiple AR content items to see how the different AR content itemswill modify the stored clip. For example, multiple AR content items thatapply different pseudorandom movement models can be applied to the samecontent by selecting different AR content items for the content.Similarly, real-time video capture may be used with an illustratedmodification to show how video images currently being captured bysensors of a client device 102 would modify the captured data. Such datamay simply be displayed on the screen and not stored in memory, or thecontent captured by the device sensors may be recorded and stored inmemory with or without the modifications (or both). In some systems, apreview feature can show how different AR content items will look withindifferent windows in a display at the same time. This can, for example,enable multiple windows with different pseudorandom animations to beviewed on a display at the same time.

Data and various systems using AR content items or other such transformsystems to modify content using this data can thus involve detection ofreal-world objects (e.g., faces, hands, bodies, cats, dogs, surfaces,objects, etc.), tracking of such objects as they leave, enter, and movearound the field of view in video frames, and the modification ortransformation of such objects as they are tracked. In various examples,different methods for achieving such transformations may be used. Someexamples may involve generating a 3D mesh model of the object or objectsand using transformations and animated textures of the model within thevideo to achieve the transformation. In other examples, tracking ofpoints on an object may be used to place an image or texture (which maybe 2D or 3D) at the tracked position. In still further examples, neuralnetwork analysis of video frames may be used to place images, models, ortextures in content (e.g., images or frames of video). AR content itemsor elements thus refer both to the images, models, and textures used tocreate transformations in content, as well as to additional modeling andanalysis information needed to achieve such transformations with objectdetection, tracking, and placement.

Real-time video processing can be performed with any kind of video data(e.g., video streams, video files, etc.) saved in a memory of acomputerized system of any kind. For example, a user can load videofiles and save them in a memory of a device or can generate a videostream using sensors of the device. Additionally, any objects can beprocessed using a computer animation model, such as a human's face andparts of a human body, animals, or non-living things such as chairs,cars, or other objects.

In some examples, when a particular modification is selected along withcontent to be transformed, elements to be transformed are identified bythe computing device and then detected and tracked if they are presentin the frames of the video. The elements of the object are modifiedaccording to the request for modification, thus transforming the framesof the video stream. Transformation of frames of a video stream can beperformed by different methods for different kinds of transformation.For example, for transformations of frames mostly referring to changingforms of an object's elements, characteristic points for each element ofan object are calculated (e.g., using an Active Shape Model (ASM) orother known methods). Then, a mesh based on the characteristic points isgenerated for each of the at least one element of the object. This meshis used in the following stage of tracking the elements of the object inthe video stream. In the process of tracking, the mentioned mesh foreach element is aligned with a position of each element. Then,additional points are generated on the mesh. A first set of first pointsis generated for each element based on a request for modification, and aset of second points is generated for each element based on the set offirst points and the request for modification. Then, the frames of thevideo stream can be transformed by modifying the elements of the objecton the basis of the sets of first and second points and the mesh. Insuch method, a background of the modified object can be changed ordistorted as well by tracking and modifying the background.

In some examples, transformations changing some areas of an object usingits elements can be performed by calculating characteristic points foreach element of an object and generating a mesh based on the calculatedcharacteristic points. Points are generated on the mesh and then variousareas based on the points are generated. The elements of the object arethen tracked by aligning the area for each element with a position foreach of the at least one element, and properties of the areas can bemodified based on the request for modification, thus transforming theframes of the video stream. Depending on the specific request formodification, properties of the mentioned areas can be transformed indifferent ways. Such modifications may involve changing color of areas;removing at least some part of areas from the frames of the videostream; including one or more new objects into areas which are based ona request for modification; and modifying or distorting the elements ofan area or object. In various examples, any combination of suchmodifications or other similar modifications may be used. For certainmodels to be animated, some characteristic points can be selected ascontrol points to be used in determining the entire state-space ofoptions for the model animation.

In some examples, two meshes associated with different objects can begenerated and deformed in correspondence to each other. A first mesh(also referred to as the body mesh) can be associated with and representmovements of a real-world object, such as a person, depicted in theimage or video. A second mesh (also referred to as an external mesh) canbe associated with an AR graphic or effect to be applied to thereal-world object. The second mesh can be associated with placementinformation that specifies how the second mesh is placed or positionedin 3D space relative to the first mesh. The placement information cancapture automatically generated correspondence information based onproximity (controlled by minimum or maximum distance thresholds ornumber of controlling vertices) between one or more vertices of thefirst mesh and one or more vertices of the second mesh. The placementinformation can also be specified in terms of UV space information thatindicates how close or how far to place the second mesh in the UV spacerelative to UV coordinates of the first mesh. The placement informationcan also specify a first set of portions to deform based on movement ofthe corresponding first mesh and a second set of portions to deformbased on a deformation parameter. As the first mesh is deformed in realtime during capture of the image or video, the first and second sets ofportions of the second mesh are similarly deformed to effectuate achange to the corresponding AR graphic that is rendered for display inthe image or video.

In some examples of a computer animation model to transform image datausing body/person detection, the body/person is detected on an imagewith use of a specific body/person detection algorithm (e.g., 3D humanpose estimation and mesh reconstruction processes). Then, an ASMalgorithm is applied to the body/person region of an image to detectbody/person feature reference points.

Other methods and algorithms suitable for body/person detection can beused. For example, in some examples, features are located using alandmark, which represents a distinguishable point present in most ofthe images under consideration. For body/person landmarks, for example,the location of the left arm may be used. If an initial landmark is notidentifiable, secondary landmarks may be used. Such landmarkidentification procedures may be used for any such objects. In someexamples, a set of landmarks forms a shape. Shapes can be represented asvectors using the coordinates of the points in the shape. One shape isaligned to another with a similarity transform (allowing translation,scaling, and rotation) that minimizes the average Euclidean distancebetween shape points. The mean shape is the mean of the aligned trainingshapes.

In some examples, a search is started for landmarks from the mean shapealigned to the position and size of the body/person determined by aglobal body/person detector. Such a search then repeats the steps ofsuggesting a tentative shape by adjusting the locations of shape pointsby template matching of the image texture around each point and thenconforming the tentative shape to a global shape model until convergenceoccurs. In some systems, individual template matches are unreliable, andthe shape model pools the results of the weak template matches to form astronger overall classifier. The entire search is repeated at each levelin an image pyramid, from coarse to fine resolution.

A transformation system can capture an image or video stream on a clientdevice (e.g., the client device 102) and perform complex imagemanipulations locally on the client device 102 while maintaining asuitable user experience, computation time, and power consumption. Thecomplex image manipulations may include size and shape changes, emotiontransfers (e.g., changing a face from a frown to a smile), statetransfers (e.g., aging a subject, reducing apparent age, changinggender), style transfers, graphical element application, 3D human poseestimation, 3D body mesh reconstruction, and any other suitable image orvideo manipulation implemented by a convolutional neural network thathas been configured to execute efficiently on the client device 102.

In some examples, a computer animation model to transform image data canbe used by a system where a user may capture an image or video stream ofthe user (e.g., a selfie) using a client device 102 having a neuralnetwork operating as part of a messaging client 104 operating on theclient device 102. The transformation system operating within themessaging client 104 determines the presence of a body/person within theimage or video stream and provides modification icons associated with acomputer animation model to transform image data, or the computeranimation model can be present as associated with an interface describedherein. The modification icons include changes that may be the basis formodifying the user's body/person within the image or video stream aspart of the modification operation. Once a modification icon isselected, the transformation system initiates a process to convert theimage of the user to reflect the selected modification icon (e.g.,generate a smiling face on the user). A modified image or video streammay be presented in a graphical user interface displayed on the clientdevice 102 as soon as the image or video stream is captured and aspecified modification is selected. The transformation system mayimplement a complex convolutional neural network on a portion of theimage or video stream to generate and apply the selected modification.That is, the user may capture the image or video stream and be presentedwith a modified result in real-time or near real-time once amodification icon has been selected. Further, the modification may bepersistent while the video stream is being captured and the selectedmodification icon remains toggled. Machine-taught neural networks may beused to enable such modifications.

The graphical user interface, presenting the modification performed bythe transformation system, may supply the user with additionalinteraction options. Such options may be based on the interface used toinitiate the content capture and selection of a particular computeranimation model (e.g., initiation from a content creator userinterface). In various examples, a modification may be persistent afteran initial selection of a modification icon. The user may toggle themodification on or off by tapping or otherwise selecting the body/personbeing modified by the transformation system and store it for laterviewing or browse to other areas of the imaging application. Wheremultiple faces are modified by the transformation system, the user maytoggle the modification on or off globally by tapping or selecting asingle body/person modified and displayed within a graphical userinterface. In some examples, individual bodies/persons, among a group ofmultiple bodies/persons, may be individually modified, or suchmodifications may be individually toggled by tapping or selecting theindividual body/person or a series of individual bodies/personsdisplayed within the graphical user interface.

A story table 314 stores data regarding collections of messages andassociated image, video, or audio data, which are compiled into acollection (e.g., a story or a gallery). The creation of a particularcollection may be initiated by a particular user (e.g., each user forwhich a record is maintained in the entity table 306). A user may createa “personal story” in the form of a collection of content that has beencreated and sent/broadcast by that user. To this end, the user interfaceof the messaging client 104 may include an icon that is user-selectableto enable a sending user to add specific content to his or her personalstory.

A collection may also constitute a “live story,” which is a collectionof content from multiple users that is created manually, automatically,or using a combination of manual and automatic techniques. For example,a “live story” may constitute a curated stream of user-submitted contentfrom various locations and events. Users whose client devices havelocation services enabled and are at a common location event at aparticular time may, for example, be presented with an option, via auser interface of the messaging client 104, to contribute content to aparticular live story. The live story may be identified to the user bythe messaging client 104, based on his or her location. The end resultis a “live story” told from a community perspective.

A further type of content collection is known as a “location story,”which enables a user whose client device 102 is located within aspecific geographic location (e.g., on a college or university campus)to contribute to a particular collection. In some examples, acontribution to a location story may require a second degree ofauthentication to verify that the end user belongs to a specificorganization or other entity (e.g., is a student on the universitycampus).

As mentioned above, the video table 304 stores video data that, in oneexample, is associated with messages for which records are maintainedwithin the message table 302. Similarly, the image table 312 storesimage data associated with messages for which message data is stored inthe entity table 306. The entity table 306 may associate variousaugmentations from the augmentation table 310 with various images andvideos stored in the image table 312 and the video table 304.

Trained machine learning technique(s) 307 stores parameters that havebeen trained during training of the external mesh deformation system224. For example, trained machine learning techniques 307 stores thetrained parameters of one or more neural network machine learningtechniques.

Data Communications Architecture

FIG. 4 is a schematic diagram illustrating a structure of a message 400,according to some examples, generated by a messaging client 104 forcommunication to a further messaging client 104 or the messaging server118. The content of a particular message 400 is used to populate themessage table 302 stored within the database 126, accessible by themessaging server 118. Similarly, the content of a message 400 is storedin memory as “in-transit” or “in-flight” data of the client device 102or the application servers 114. A message 400 is shown to include thefollowing example components:

-   -   message identifier 402: a unique identifier that identifies the        message 400.    -   message text payload 404: text, to be generated by a user via a        user interface of the client device 102, and that is included in        the message 400.    -   message image payload 406: image data, captured by a camera        component of a client device 102 or retrieved from a memory        component of a client device 102, and that is included in the        message 400. Image data for a sent or received message 400 may        be stored in the image table 312.    -   message video payload 408: video data, captured by a camera        component or retrieved from a memory component of the client        device 102, and that is included in the message 400. Video data        for a sent or received message 400 may be stored in the video        table 304.    -   message audio payload 410: audio data, captured by a microphone        or retrieved from a memory component of the client device 102,        and that is included in the message 400.    -   message augmentation data 412: augmentation data (e.g., filters,        stickers, or other annotations or enhancements) that represents        augmentations to be applied to message image payload 406,        message video payload 408, or message audio payload 410 of the        message 400. Augmentation data for a sent or received message        400 may be stored in the augmentation table 310.    -   message duration parameter 414: parameter value indicating, in        seconds, the amount of time for which content of the message        (e.g., the message image payload 406, message video payload 408,        message audio payload 410) is to be presented or made accessible        to a user via the messaging client 104.    -   message geolocation parameter 416: geolocation data (e.g.,        latitudinal and longitudinal coordinates) associated with the        content payload of the message. Multiple message geolocation        parameter 416 values may be included in the payload, each of        these parameter values being associated with respect to content        items included in the content (e.g., a specific image within the        message image payload 406, or a specific video in the message        video payload 408).    -   message story identifier 418: identifier values identifying one        or more content collections (e.g., “stories” identified in the        story table 314) with which a particular content item in the        message image payload 406 of the message 400 is associated. For        example, multiple images within the message image payload 406        may each be associated with multiple content collections using        identifier values.    -   message tag 420: each message 400 may be tagged with multiple        tags, each of which is indicative of the subject matter of        content included in the message payload. For example, where a        particular image included in the message image payload 406        depicts an animal (e.g., a lion), a tag value may be included        within the message tag 420 that is indicative of the relevant        animal. Tag values may be generated manually, based on user        input, or may be automatically generated using, for example,        image recognition.    -   message sender identifier 422: an identifier (e.g., a messaging        system identifier, email address, or device identifier)        indicative of a user of the client device 102 on which the        message 400 was generated and from which the message 400 was        sent.    -   message receiver identifier 424: an identifier (e.g., a        messaging system identifier, email address, or device        identifier) indicative of a user of the client device 102 to        which the message 400 is addressed.

The contents (e.g., values) of the various components of message 400 maybe pointers to locations in tables within which content data values arestored. For example, an image value in the message image payload 406 maybe a pointer to (or address of) a location within an image table 312.Similarly, values within the message video payload 408 may point to datastored within a video table 304, values stored within the messageaugmentation data 412 may point to data stored in an augmentation table310, values stored within the message story identifier 418 may point todata stored in a story table 314, and values stored within the messagesender identifier 422 and the message receiver identifier 424 may pointto user records stored within an entity table 306.

External Mesh Deformation System

FIG. 5 is a block diagram showing an example external mesh deformationsystem 224, according to example examples. External mesh deformationsystem 224 includes a set of components 510 that operate on a set ofinput data (e.g., a monocular image depicting a real-world object, suchas a person or training data). The set of input data is obtained fromone or more database(s) (FIG. 3 ) during the training phases and isobtained from an RGB camera of a client device 102 when an AR/VRapplication is being used, such as by a messaging client 104. Externalmesh deformation system 224 includes a machine learning technique module512, a skeletal key-points module 511, a body mesh module 514, an imagemodification module 518, an AR effect module 519, an external meshmodule 530, a deformation parameter module 532, a 3D body trackingmodule 513, a whole-body segmentation module 515, and an image displaymodule 520.

During training, the external mesh deformation system 224 receives agiven training image or video from training data 501. The external meshdeformation system 224 applies one or more machine learning techniquesusing the machine learning technique module 512 on the given trainingimage or video. The machine learning technique module 512 extracts oneor more features from the given training image or video to estimate a 3Dbody mesh of the person(s) or user(s) depicted in the image or video.

The machine learning technique module 512 retrieves 3D body meshinformation associated with the given training image or video. Themachine learning technique module 512 compares the estimated 3D bodymesh with the ground truth garment 3D body mesh provided as part of thetraining data 502. Based on a difference threshold or deviation of thecomparison, the machine learning technique module 512 updates one ormore coefficients or parameters and obtains one or more additionaltraining images or videos. After a specified number of epochs or batchesof training images have been processed and/or when the differencethreshold or deviation reaches a specified value, the machine learningtechnique module 512 completes training and the parameters andcoefficients of the machine learning technique module 512 are stored inthe trained machine learning technique(s) 307.

In some examples, during training, the machine learning technique module512 receives 2D skeletal joint information from a skeletal key-pointsmodule 511. The skeletal key-points module 511 tracks skeletal keypoints of a user depicted in a given training image (e.g., head joint,shoulder joints, hip joints, leg joints, and so forth) and provides the2D or 3D coordinates of the skeletal key points. This information isused by the machine learning technique module 512 to identifydistinguishing attributes of the user depicted in the training image andto generate the 3D body mesh.

The 3D body mesh generated by the machine learning technique module 512is provided to the body mesh module 514. The body mesh module 514 cantrack the object depicted in the image or video and update the 3D bodymesh associated with the object. In an example, the body mesh module 514can track the object based on 3D body tracking information provided bythe 3D body tracking module 513. The body mesh module 514 can update the3D body mesh in 3D and can adjust a position, body type, rotation, orany other parameter of the 3D body mesh. FIG. 6 is a diagrammaticrepresentation of outputs of the external mesh deformation system 224,in accordance with some examples. Specifically, FIG. 6 shows a 3D bodymesh 600 generated and tracked by the body mesh module 514. In oneexample, the body mesh module 514 can track changes of the 3D body meshacross frames of the video. The body mesh module 514 can provide changesto the 3D body mesh to the external mesh module 530 to update and deformthe external mesh based on changes to the 3D body mesh as the 3D bodymesh is being blended into the external mesh.

The external mesh module 530 can generate an external mesh based on a 3Dbody mesh received from the body mesh module 514. The external meshmodule 530 can also generate a corresponding AR graphic that representsthe person or user associated with the 3D body mesh. In an example, theexternal mesh module 530 can convert an image or video into UV pixelvalues. The external mesh module 530 can identify a portion of the imageor video that corresponds to the person or user depicted in the image orvideo. The external mesh module 530 can obtain the UV pixel values ofthe portion of the image corresponding to the person or user depicted inthe image or video. The external mesh module 530 can then generate atexture for an AR graphic that mirrors or includes a copy of theobtained UV pixel values. The external mesh module 530 also generates acopy of the 3D body mesh received from the body mesh module 514 and usesthat copy as the external mesh. The external mesh module 530 cangenerate correspondence information between the external mesh and the 3Dbody mesh in order to update changes to the external mesh (andcorresponding AR graphic) as the user or person moves around the imageor video (represented by movements of the 3D body mesh).

In an example, the body mesh module 514 can determine a first set ofcoordinates of the 3D body mesh in a normal-tangent space for a firstframe of the frames of the video and can determine a second set ofcoordinates of the 3D body mesh in the normal-tangent space for a secondframe of the frames of the video. The body mesh module 514 can compute,in real time, a change between the first and second sets of coordinatesin the normal-tangent space and can transfer the change between thefirst and second sets of coordinates in the normal-tangent space to theexternal mesh module 530. Specifically, the external mesh module 530 canupdate and adjust a 3D position and a 3D orientation of the externalmesh based on the change between the first and second sets ofcoordinates in the normal-tangent space. In this way, the external meshmodule 530 can deform the external mesh associated with an AR graphicwithout using a rig or bone information of the real-world object.

In an example, the external mesh module 530 can compute a rate at whichthe first set of coordinates changes to the second set of coordinates inthe normal-tangent space (or any other suitable space). The externalmesh module 530 can deform the external mesh based on the rate at whichthe first set of coordinates changes to the second set of coordinates inthe normal-tangent space (or any other suitable space). For example, ifthe person depicted in the image or video turns or twists at aparticular rate or speed, the body mesh module 514 can compute a firstrate that represents the direction and the speed at which the personturns or twists. This first rate is provided to the external mesh module530, which then changes or deforms the external mesh based on the firstrate.

The external mesh module 530 can receive an indication of an ARexperience from the AR effect module 519. The AR effect module 519 canreceive a user input that selects a given deformation parameter that isused to adjust the AR graphic that represents the person or userdepicted in the image or video. The AR effect module 519 can provide thedeformation parameter to the deformation parameter module 532. In somecases, the user input can specify a blending parameter, which is alsostored in the deformation parameter module 532.

The external mesh module 530 can obtain placement information for theexternal mesh. The placement information can specify where to place theAR graphic in the image or video in relation to or relative to thereal-world object, which portions of the AR graphic are deformed basedon movement of the real-world object, and a blending parameter for theexternal mesh. The placement information can include the currentposition and orientation of the user or person depicted in the image orvideo, such that the external mesh is placed over the person or userdepicted in the image or video. The blending parameter can include alinear or non-linear function that controls a rate indicating howquickly or slowly the real-world object portion is blended into the ARgraphic. The AR graphic can also include information indicating whichportions of the 3D body mesh to blend into the AR graphic and whichportions to not change. In this way, the external mesh module 530 cancommunicate with the body mesh module 514 to modify the body mesh moduleto blend into the external mesh. Specifically, the 3D body mesh cancorrespond to a real-world person. In such cases, the image or video canbe modified to depict the portion of the real-world person being changedinto the AR element, such as by animating the body part of the persondepicted in the video being morphed into the AR element. The morphing ofthe body part of the person can take into account movement of the bodypart while the morphing takes place and pose information of the bodypart or person.

In one example, the placement information can specify an edge or bodypart of the 3D body mesh corresponding to the real-world graphic (e.g.,a left arm, a right arm, a head, and so forth) that is attached to oroverlaps the external mesh. The placement information can also specify aminimum distance between the edge or body part away from which an edgeof the corresponding AR graphic (the external mesh) can be rendered fordisplay. In response, the external mesh module 530 can maintain theposition of the external mesh (and corresponding AR graphic), throughouta plurality of video frames, at least the minimum distance away from theedge or body part of the body mesh. The position of the external meshcan be maintained relative to the 3D body mesh while the 3D body mesh isbeing blended or transformed into the external mesh.

In one example, the placement information can specify an edge or bodypart of the body mesh corresponding to the real-world graphic (e.g., aleft arm, a right arm, a head, and so forth) that is attached to oroverlaps the external mesh. The placement information can also specify amaximum distance between the edge or body part away from which an edgeof the corresponding AR graphic (external mesh) can be rendered fordisplay. In response, the external mesh module 530 can maintain theposition of the external mesh (and corresponding AR graphic) throughouta plurality of video frames at most the maximum distance away from theedge or body part of the body mesh. In this way, the position of theexternal mesh can be maintained relative to the 3D body mesh while the3D body mesh is being blended or transformed into the external mesh.

In one example, the placement information can specify an edge or bodypart of the body mesh corresponding to the real-world graphic (e.g., aleft arm, a right arm, a head, and so forth) that is attached to theexternal mesh. The placement information can also specify a range ofdistances between the edge or body part away from which an edge of thecorresponding AR graphic (external mesh) can be rendered for display. Inresponse, the external mesh module 530 can maintain the position of theexternal mesh (and corresponding AR graphic) throughout a plurality ofvideo frames between minimum and maximum values of the range ofdistances away from the edge or body part of the body mesh. In this way,the position of the external mesh can be maintained relative to the 3Dbody mesh while the 3D body mesh is being blended or transformed intothe external mesh. The placement information can specify which bodypart, UV channel coordinates, voxels, or other position information ofthe 3D body mesh to deform or blend into the external mesh. In suchcases, the body mesh module 514 receives the placement information andcan deform, blend, transform, or change the portions of the 3D body meshthat are specified into the external mesh.

In one example, the placement information can specify relative UVchannel coordinates of the 3D body mesh that is to be transformed orblended into the external mesh. The relative UV channel coordinates canbe used to maintain and place the external mesh (and corresponding ARgraphic) within the image or video depicting an object and to identifywhich portions of the 3D body mesh to blend into the external mesh. Inthis case, the external mesh module 530 can obtain UV channelcoordinates of the 3D body mesh corresponding to the real-world objectdepicted in the image or video. The external mesh module 530 can alsocompute a set of UV channel coordinates of the external mesh based onthe UV coordinates associated with the 3D body mesh and the relative UVchannel coordinates in the placement information. For example, theplacement information can specify a minimum or maximum distance awayfrom a particular UV channel coordinate of the 3D body mesh at which theexternal mesh can be placed. In response, the external mesh module 530can place the external mesh at a set of UV channel coordinates that arewithin the minimum or maximum distances from the UV coordinates of the3D body mesh. In addition, the 3D body mesh portions within the minimumor maximum distances from the UV coordinates are blended or changed intothe external mesh. As a result, the corresponding AR graphic associatedwith the external mesh can be used to blend, into the AR graphic, aportion of the real-world object depicted in the image or video at theposition that corresponds to the set of UV coordinates. The portion ofthe real-world object can be blended or morphed into the AR graphicwhile the real-world object moves around the video, specifically basedon movement information received from the body mesh module 514.

Based on the placement information and changes detected for the 3D bodymesh, the external mesh module 530 can deform the external mesh incorrespondence to the changes detected in the 3D body mesh. In oneexample, the external mesh can be deformed to change the position in 3Drelative to the 3D body mesh in response to detecting a change in 3Dposition of the 3D body mesh while the 3D body mesh is being morphed orblended into the external mesh. For example, if the 3D body mesh isdetermined to move along a first axis by a first amount, the externalmesh is similarly moved along the first axis by the first amount (orsome other amount that is computed as a factor of the first amount)while some portion of the 3D body mesh is being morphed or blended intothe external mesh. As another example, the external mesh can be rotatedor twisted in a corresponding manner as the 3D body mesh. Specifically,if the 3D body mesh is determined to rotate along a rotational axis by asecond amount, the external mesh is similarly rotated along therotational axis by the second amount (or some other amount that iscomputed as a factor of the second amount) while some other portion ofthe 3D body mesh is being morphed or blended into the external mesh.

As another example, the external mesh can be deformed based on changesto the body shape, body state, or body properties across frames of theimage or video. Specifically, if a portion of the 3D body mesh isreduced in size (e.g., a waist is indented by a specified amount as aresult of an external force, such as a hand being placed on the waist),the corresponding portion of the external mesh is also reduced in sizeor repositioned in 3D space by the same amount or other specifiedamount. Such changes are also reflected in the morphing or blending ofthe 3D body model into the external mesh. In this way, if the resultingportion of the real-world object is being changed in real-time (e.g., asa result of the external force), the corresponding AR graphic into whichthe portion of the real-world object is also changed in a similar mannerin real time. In another example, the 3D body mesh can periodicallyexpand and contract a chest portion of the 3D body mesh (or upper bodyportion) based on a breathing cycle of the person depicted in the image.In such cases, the corresponding portion of the external mesh into whichthe 3D body mesh is blended, morphed, or transformed is also deformed toexpand and contract in size in correspondence with the breathing cycle.

In an example, the body mesh module 514 can compute changes in theNormal-Tangent space of the corresponding object. Namely, the body meshmodule 514 can determine movement of the 3D body mesh in theNormal-Tangent space and can provide indications of that movement to theexternal mesh module 530. The external mesh module 530 can apply changesto the external mesh based on the movement in the Normal-Tangent space.In this way, the 3D body mesh can be blended, morphed, changed, ortransformed into the external mesh based on changes in theNormal-Tangent space of the corresponding object.

The deformation parameter module 532 can specify one or more changes tomake to the AR graphic. For example, the deformation parameter module532 can specify an amount by which a waist portion of a body representedby the AR graphic is to be reduced or increased. In such cases, theexternal mesh module 530 can change the waist portion of the externalmesh to increase or reduce the size by the specified amount. As aresult, the corresponding AR graphic is also changed to have a larger orsmaller waist portion, such as by deleting certain pixels from thetexture or adding more pixels to the texture by copying or blendingpixels values from the edges of the waist portion to the enlarged waistportion. Specifically, the external mesh module 530 can determine thatthe deformation parameter specifies to increase the waist portion by acertain amount. In response, the external mesh module 530 can expandonly the waist portion of the external mesh and leave other portions ofthe external mesh unchanged. The external mesh module 530 can draw aborder around the portion of the external mesh being enlarged andidentify the corresponding region of the AR graphic including thetexture of the portion being enlarged. The external mesh module 530 canobtain the pixel values or an average of the pixel values around theborder or edges of the AR graphic. The waist portion of the AR graphicoriginally can be a polygon having a first size. After increasing thewaist size of the external mesh, the waist portion of the AR graphic isincreased in size resulting in a polygon having a second size that isgreater than the first size. In order to populate the pixels in thespace region between edges of the polygon having the first size to thepolygon having the second size, the pixel values around the border oredges can be blended in or copied into the space region. This results ina realistic view of the AR graphic having a larger waist portion becausethe smaller waist and larger waste have similar pixel values. Thedeformation parameter module 532 can then instruct the AR effect module519 to replace the portion of the image or video depicting the person oruser with the AR graphic that represents the person or user with thelarger waist portion.

As another example, in addition to changing the waist portion (or afirst portion of the external mesh or AR graphic) or instead of changingthe waist portion of the first portion of the external mesh or ARgraphic (or making any other changes discussed above), the deformationparameter module 532 can specify another amount by which to change asecond portion of the AR graphic. For example, the deformation parametermodule 532 can specify an amount by which a neck portion of a bodyrepresented by the AR graphic is to be reduced. In such cases, theexternal mesh module 530 can change the neck portion of the externalmesh to reduce the size by the specified amount. This can be performedsimultaneously with changing the waist or first portion, after changingthe waist or first portion, or instead of changing the waist or firstportion. As a result, the corresponding AR graphic is also changed tohave a smaller neck portion, such as by deleting certain pixels from thetexture corresponding to the neck portion. Specifically, the externalmesh module 530 can determine that the deformation parameter specifiesto decrease the neck portion by a given amount. In response, theexternal mesh module 530 can reduce only the neck portion of theexternal mesh and leave other portions of the external mesh unchanged(except such other portions specified to change by the deformationparameter module 532 by another amount). The external mesh module 530can draw a border around the portion of the external mesh being reducedand identify the corresponding region of the AR graphic including thetexture of the portion being reduced. The neck portion of the AR graphicoriginally can be a polygon having a first size. After decreasing theneck size of the external mesh, the neck portion of the AR graphic isdecreased in size resulting in a polygon having a second size that issmaller than the first size. This results in a realistic view of the ARgraphic having a shorter neck portion. The deformation parameter module532 can then instruct the AR effect module 519 to replace the portion ofthe image or video depicting the person or user with the AR graphic thatrepresents the person or user with the smaller or shorter neck portion.

As another example, in addition to changing the waist portion (or afirst portion of the external mesh or AR graphic) or instead of changingthe waist portion of the first portion of the external mesh or ARgraphic (or making any other changes discussed above), the deformationparameter module 532 can specify a color change for a third portion ofthe AR graphic. For example, the deformation parameter module 532 canspecify a new color for a leg portion of a body represented by the ARgraphic. In such cases, the external mesh module 530 can change thecolor of the leg portion of the AR graphic corresponding to the externalmesh to the specified color. This can be performed simultaneously withchanging the waist or first portion, after changing the waist or firstportion, or instead of changing the waist or first portion. As a result,the leg portion of the AR graphic is changed to have a different colorwhile tracking movement of the leg portion through the external meshbased on movement of the person or user depicted in the image or video.The deformation parameter module 532 can then instruct the AR effectmodule 519 to replace the portion of the image or video depicting theperson or user with the AR graphic that represents the person or userwith the different color leg portion.

As another example, in addition to changing the waist portion (or afirst portion of the external mesh or AR graphic) or instead of changingthe waist portion of the first portion of the external mesh or ARgraphic (or making any other changes discussed above), the deformationparameter module 532 can specify an AR element to add to a fourthportion of the AR graphic. For example, the deformation parameter module532 can specify an AR tattoo (e.g., an image, video, graphical element,emoji, and so forth) to add to an arm portion of a body represented bythe AR graphic. In such cases, the external mesh module 530 can changethe portion of the arms of the AR graphic corresponding to the externalmesh to include the specified AR graphic. This can be performedsimultaneously with changing the waist or first portion, after changingthe waist or first portion, or instead of changing the waist or firstportion. As a result, the arm portion of the AR graphic is changed tohave an AR element while tracking movement of the arm portion throughthe external mesh based on movement of the person or user depicted inthe image or video. The deformation parameter module 532 can theninstruct the AR effect module 519 to replace the portion of the image orvideo depicting the person or user with the AR graphic that representsthe person or user with the AR element added to the arm.

The deformation parameter module 532 can control the rate at which the3D body mesh portion corresponding to the external mesh is transformed,blended, or changed into the external mesh. For example, the deformationparameter module 532 can control blending of the 3D body mesh portioninto the external mesh according to a linear function. In such cases,the portion of the 3D body mesh is blended into the external meshlinearly in time. Specifically, the linear function can specify amaximum time interval used to effectuate the blending, such as 5seconds. In such cases, the 3D body mesh portion is transformed into theexternal mesh at a rate that results in completion of the transformationafter 5 seconds elapses.

In another example, the deformation parameter module 532 can controlblending of the 3D body mesh portion into the external mesh according toa non-linear function. In such cases, the portion of the 3D body meshcan be linearly blended into the external mesh at a first rate for afirst portion of the given time interval to create a partially morphed3D body mesh. After the first portion of the given time intervalelapses, the partially morphed 3D body mesh continues to be blended intothe external mesh at a second rate for a second portion of the giventime interval. For example, a head portion of the 3D body mesh can beblended into a first portion of the external mesh at a first rate, suchas to complete within a first time interval of 5 seconds. Then, a legsportion of the 3D body mesh can be blended into a second portion of theexternal mesh at a second rate, such as to complete within a second timeinterval of 2 seconds or 10 seconds. The second rate can be faster orslower than the first rate. In another example, the head portion of the3D body mesh can be partially blended into the external mesh at thefirst rate so that the head portion does not completely blend into theexternal mesh at the end of the first time interval. Then after thefirst time interval elapses, the partially blended head portion cancontinue to be blended into the external mesh at a second faster orslower rate to completely blend into the external mesh.

In some examples, the body mesh module 514 communicates with thedeformation parameter module 532 to control the rate at which theportions of the 3D body mesh are morphed or blended into the externalmesh that is being deformed by the external mesh module 530. Forexample, the deformation parameter module 532 can compute a blendingcompletion progress representing how much of the 3D body mesh has beenblended into the external mesh over a time period. The blendingcompletion progress can be represented as a percentage of pixels orvoxels within a specified region of the 3D body mesh that match theexternal mesh relative to pixels or voxels that match the 3D body mesh.As the number of pixels or voxels in the specified region of the 3D bodymesh increases over time, the blending completion progress alsoincreases. Blending is determined to be complete when a threshold numberor percentage of pixels or voxels in the specified region of the 3D bodymesh matches the corresponding pixels or voxels of the external mesh.

For example, in response to determining that the blending completionprogress is less than the threshold value, the portion of the 3D bodymesh is linearly blended into the external mesh at a first rate tocreate a partially morphed 3D body mesh. The blending completionprogress continues to be computed and measured, such as after thepartially morphed 3D body mesh is completed. In an example, the blendingcompletion progress can be determined to have reached the thresholdvalue (e.g., more than 50 percent of the pixels in a head portion of the3D body mesh match a head portion of the external mesh) and, inresponse, the first rate at which the partially morphed 3D body meshcontinues to be blended into the external mesh is modified, such asincreased or decreased. In some cases, the first rate is increased tocause the partially morphed 3D body mesh to continue to be blended intothe external mesh at a faster pace than an initial pace. In some cases,the first rate is decreased to cause the partially morphed 3D body meshto continue to be blended into the external mesh at a slower pace thanan initial pace.

In an example, the deformation parameter module 532 can compute ablending completion progress representing how much of the 3D body meshhas been blended into the external mesh over a time period. In responseto determining that the blending completion progress is less than thethreshold value (e.g., less than 50 percent of the pixels in a headportion of the 3D body mesh match a head portion of the external mesh),the portion of the 3D body mesh is linearly blended into the externalmesh at a first rate to create a partially morphed 3D body mesh. Theblending completion progress continues to be computed and measured, suchas after the partially morphed 3D body mesh is completed. In an example,the blending completion progress can be determined to have reached thethreshold value (e.g., more than 50 percent of the pixels in a headportion of the 3D body mesh match a head portion of the external mesh)and, in response, the partially morphed 3D body mesh continues to beblended into the external mesh according to a springing effect, such asto instantly be morphed into the external mesh. This way, a head portionof the 3D body mesh, for example, can start being blended slowly into ahead portion of the external mesh over an initial period of time, suchas 3 seconds. After the 3 seconds elapses, when the 3D body mesh portionis partially blended into the external mesh (but not completely), theremaining portion of the 3D body mesh is instantly bounded or morphedinto the external mesh.

In an example, the AR effect selection module 519 selects and appliesone or more AR elements or graphics to an object depicted in the imageor video based on the body mesh associated with the object received fromthe body mesh module 514. These AR graphics combined with the real-worldobject depicted in the image or video are provided to the imagemodification module 518 to render an image or video that depicts theperson wearing the AR object, such as an AR purse or earrings.

The image modification module 518 can adjust the image captured by thecamera based on the AR effect selected by the visual effect selectionmodule 519. The image modification module 518 adjusts the way in whichthe AR garment(s) or fashion accessory placed over the user or persondepicted in the image or video is/are presented in an image or video,such as by changing the physical properties (deformation) of the ARgarment or fashion accessory based on the changes to the 3D body mesh ofthe user and an external force simulation and applying one or more ARelements (AR graphical elements). Image display module 520 combines theadjustments made by the image modification module 518 into the receivedmonocular image or video depicting the user's body. The image or videois provided by the image display module 520 to the client device 102 andcan then be sent to another user or stored for later access and display.

In some examples, the image modification module 518 can receive 3D bodytracking information representing the 3D positions of the user depictedin the image from the 3D body tracking module 513. The 3D body trackingmodule 513 generates the 3D body tracking information by processing thetraining data 501 using additional machine learning techniques. Theimage modification module 518 can also receive a whole-body segmentationrepresenting which pixels in the image correspond to the whole body ofthe user from another machine learning technique. The whole-bodysegmentation can be received from the whole-body segmentation module515. The whole-body segmentation module 515 generates the whole-bodysegmentation by processing the training data 501 using a machinelearning technique.

In one example, as shown in FIG. 7 , the AR effect selection module 519can apply one or more AR effects to an object depicted in an image orvideo 700 corresponding to a 3D body mesh 710 captured by a clientdevice 102 using an external mesh 720. The AR effect selection module519 can receive input requesting to change or blend a portion of theobject into the external mesh or AR effect. The input can select whichportion of the object to blend, the rate at which to blend the object,and/or can just identify an AR effect for which the rate and position ofthe object are automatically determined.

The external mesh 720 can include a portion that is attached to oroverlaps the 3D body mesh 710. In an example, the external mesh 720 canrepresent an AR person, AR animal, AR graphic, AR element, AR component,AR image, AR video, AR character, AR avatar, or other real-world object.For example, the external mesh module 530 can receive the 3D body mesh710. The external mesh module 530 can generate the external mesh 720 tomirror the position, orientation, and physical attributes of the 3D bodymesh 710. The external mesh module 530 can generate placementinformation 740 associated with the external mesh 720 based on thecurrent position and orientation of the 3D body mesh 710. This way, theexternal mesh can be used to replace a depiction of the user or personin the image or video with the AR graphic that represents changes to theperson or user. The placement information 740 can specify proximityparameters 742, UV channel coordinates 744, and/or deformation parameter746. Based on the placement information 740, the external mesh module530 can specify where to place and position the external mesh 720 (andthe corresponding AR graphic 730) in the image or video and whichportions of the 3D body mesh 710 to blend or morph into the externalmesh 720. Based on the placement information 740, the external meshmodule 530 can instruct the deformation parameter module 532 on the rateand function used to control the transforming, blending, morphing, orchanging of the 3D body mesh 710 into the external mesh 720.

The external mesh module 530 can also generate an AR graphic 730 thatrepresents visual attributes of the person or user depicted in the imageor video. Namely, the external mesh module 530 can obtain UV channelpixel values of the person depicted in the image or video. The externalmesh module 530 can copy those UV channel or pixel values into a textureassociated with the AR graphic 730. This way, the AR graphic 730 looksthe same as the person or user depicted in the image or video. The ARgraphic 730 is placed over the external mesh 720 in order to present anAR visual depiction of the person or user in the image or video that hasthe same pose and visual attributes as the real-world person or user. Inthis way, as the person or user moves around the image or video, thecorresponding AR graphic 730 is similarly moved based on updates to theexternal mesh 720.

The deformation parameter 746 can specify changes, such as making armslonger, making a waist smaller, adding a graphical element, and/orchanging a color of a portion of the texture of the AR graphic 730. Theexternal mesh module 530 can modify the AR graphic 730 and/or theexternal mesh 720 based on the deformation parameter 746. In this way,the arms of the AR graphic 730 can be made to appear longer or shorterthan the arms of the real-world person corresponding to the 3D body mesh710. Or the waist of the AR graphic 730 can be made to appear smaller orlarger than the waist of the real-world person corresponding to the 3Dbody mesh 710. The deformation parameter 746 can also specify a blendingparameter that controls how quickly to change, transform, or blend thereal-world depiction of the person or user into the AR graphic thatrepresents changes to the real-world depiction of the person or user.

In an example, the external mesh module 530 can compute a correspondence722 between the external mesh 720 and the 3D body mesh 710. Thecorrespondence can be used to deform the external mesh 720 in 3D alongone or more axes 724 based on how the 3D body mesh 710 is deformed, asdiscussed above, while a portion of the 3D body mesh 710 is beingmorphed or blended into the external mesh 720. As the external meshmodule 530 deforms the external mesh 720, the corresponding AR graphic730 is similarly deformed and rendered for display within the image orvideo based on the placement information 740. Namely, as the externalmesh module 530 deforms the external mesh 720, the corresponding ARgraphic 730 into which the specified portion of the 3D body mesh isblended into is similarly deformed and rendered for display within theimage or video based on the placement information 740.

As shown in FIG. 8 , image 800 depicts a real-world person or usercaptured by a camera of a client device 102. After the external mesh isdeformed and used to transform or blend a portion of the 3D body mesh710, the corresponding AR graphic is rendered for display on the imageor video. In an example, the AR graphic replaces the depiction of thereal-world person or user, as shown in image 810. Image 810 shows thesame person as depicted in image 800 but with changes made according tothe deformation parameter 746. As an example, the arms of the personshown in image 810 are longer in the AR graphic corresponding to theperson. In addition, the belly or waist portion of the person shown inimage 810 is wider in the AR graphic corresponding to the person. Inaddition, a leg portion of the person shown in image 810 does notinclude an AR element which has been added to the leg portion in the ARgraphic corresponding to the person, such as by adding an AR tattoo tothe leg portion.

FIG. 9 is a flowchart of a process 900 performed by the external meshdeformation system 224, in accordance with some examples. Although theflowchart can describe the operations as a sequential process, many ofthe operations can be performed in parallel or concurrently. Inaddition, the order of the operations may be re-arranged. A process isterminated when its operations are completed. A process may correspondto a method, a procedure, and the like. The steps of methods may beperformed in whole or in part, may be performed in conjunction with someor all of the steps in other methods, and may be performed by any numberof different systems or any portion thereof, such as a processorincluded in any of the systems.

At operation 901, the external mesh deformation system 224 (e.g., aclient device 102 or a server) receives a video that includes adepiction of a real-world object, as discussed above.

At operation 902, the external mesh deformation system 224 generates a3D body mesh associated with the real-world object that tracks movementof the real-world object across frames of the video, as discussed above.

At operation 903, the external mesh deformation system 224 determines UVpositions of the real-world object depicted in the video to obtain pixelvalues associated with the UV positions, as discussed above.

At operation 904, the external mesh deformation system 224 generates anexternal mesh and associated AR element representing the real-worldobject based on the pixel values associated with the UV positions, asdiscussed above.

At operation 905, the external mesh deformation system 224 deforms theexternal mesh based on changes to the 3D body mesh and a deformationparameter, as discussed above.

At operation 906, the external mesh deformation system 224 modifies thevideo to replace the real-world object with the AR element based on thedeformed external mesh, as discussed above.

Machine Architecture

FIG. 10 is a diagrammatic representation of the machine 1000 withinwhich instructions 1008 (e.g., software, a program, an application, anapplet, an app, or other executable code) for causing the machine 1000to perform any one or more of the methodologies discussed herein may beexecuted. For example, the instructions 1008 may cause the machine 1000to execute any one or more of the methods described herein. Theinstructions 1008 transform the general, non-programmed machine 1000into a particular machine 1000 programmed to carry out the described andillustrated functions in the manner described. The machine 1000 mayoperate as a standalone device or may be coupled (e.g., networked) toother machines. In a networked deployment, the machine 1000 may operatein the capacity of a server machine or a client machine in aserver-client network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. The machine 1000 maycomprise, but not be limited to, a server computer, a client computer, apersonal computer (PC), a tablet computer, a laptop computer, a netbook,a set-top box (STB), a personal digital assistant (PDA), anentertainment media system, a cellular telephone, a smartphone, a mobiledevice, a wearable device (e.g., a smartwatch), a smart home device(e.g., a smart appliance), other smart devices, a web appliance, anetwork router, a network switch, a network bridge, or any machinecapable of executing the instructions 1008, sequentially or otherwise,that specify actions to be taken by the machine 1000. Further, whileonly a single machine 1000 is illustrated, the term “machine” shall alsobe taken to include a collection of machines that individually orjointly execute the instructions 1008 to perform any one or more of themethodologies discussed herein. The machine 1000, for example, maycomprise the client device 102 or any one of a number of server devicesforming part of the messaging server system 108. In some examples, themachine 1000 may also comprise both client and server systems, withcertain operations of a particular method or algorithm being performedon the server-side and with certain operations of the particular methodor algorithm being performed on the client-side.

The machine 1000 may include processors 1002, memory 1004, andinput/output (I/O) components 1038, which may be configured tocommunicate with each other via a bus 1040. In an example, theprocessors 1002 (e.g., a Central Processing Unit (CPU), a ReducedInstruction Set Computing (RISC) Processor, a Complex Instruction SetComputing (CISC) Processor, a Graphics Processing Unit (GPU), a DigitalSignal Processor (DSP), an Application Specific Integrated Circuit(ASIC), a Radio-Frequency Integrated Circuit (RFIC), another processor,or any suitable combination thereof) may include, for example, aprocessor 1006 and a processor 1010 that execute the instructions 1008.The term “processor” is intended to include multi-core processors thatmay comprise two or more independent processors (sometimes referred toas “cores”) that may execute instructions contemporaneously. AlthoughFIG. 10 shows multiple processors 1002, the machine 1000 may include asingle processor with a single-core, a single processor with multiplecores (e.g., a multi-core processor), multiple processors with a singlecore, multiple processors with multiples cores, or any combinationthereof.

The memory 1004 includes a main memory 1012, a static memory 1014, and astorage unit 1016, all accessible to the processors 1002 via the bus1040. The main memory 1004, the static memory 1014, and the storage unit1016 store the instructions 1008 embodying any one or more of themethodologies or functions described herein. The instructions 1008 mayalso reside, completely or partially, within the main memory 1012,within the static memory 1014, within machine-readable medium 1018within the storage unit 1016, within at least one of the processors 1002(e.g., within the processor's cache memory), or any suitable combinationthereof, during execution thereof by the machine 1000.

The I/O components 1038 may include a wide variety of components toreceive input, provide output, produce output, transmit information,exchange information, capture measurements, and so on. The specific I/Ocomponents 1038 that are included in a particular machine will depend onthe type of machine. For example, portable machines such as mobilephones may include a touch input device or other such input mechanisms,while a headless server machine will likely not include such a touchinput device. It will be appreciated that the I/O components 1038 mayinclude many other components that are not shown in FIG. 10 . In variousexamples, the I/O components 1038 may include user output components1024 and user input components 1026. The user output components 1024 mayinclude visual components (e.g., a display such as a plasma displaypanel (PDP), a light-emitting diode (LED) display, a liquid crystaldisplay (LCD), a projector, or a cathode ray tube (CRT)), acousticcomponents (e.g., speakers), haptic components (e.g., a vibratory motor,resistance mechanisms), other signal generators, and so forth. The userinput components 1026 may include alphanumeric input components (e.g., akeyboard, a touch screen configured to receive alphanumeric input, aphoto-optical keyboard, or other alphanumeric input components),point-based input components (e.g., a mouse, a touchpad, a trackball, ajoystick, a motion sensor, or another pointing instrument), tactileinput components (e.g., a physical button, a touch screen that provideslocation and force of touches or touch gestures, or other tactile inputcomponents), audio input components (e.g., a microphone), and the like.

In further examples, the I/O components 1038 may include biometriccomponents 1028, motion components 1030, environmental components 1032,or position components 1034, among a wide array of other components. Forexample, the biometric components 1028 include components to detectexpressions (e.g., hand expressions, facial expressions, vocalexpressions, body gestures, or eye-tracking), measure biosignals (e.g.,blood pressure, heart rate, body temperature, perspiration, or brainwaves), identify a person (e.g., voice identification, retinalidentification, facial identification, fingerprint identification, orelectroencephalogram-based identification), and the like. The motioncomponents 1030 include acceleration sensor components (e.g.,accelerometer), gravitation sensor components, rotation sensorcomponents (e.g., gyroscope).

The environmental components 1032 include, for example, one or morecameras (with still image/photograph and video capabilities),illumination sensor components (e.g., photometer), temperature sensorcomponents (e.g., one or more thermometers that detect ambienttemperature), humidity sensor components, pressure sensor components(e.g., barometer), acoustic sensor components (e.g., one or moremicrophones that detect background noise), proximity sensor components(e.g., infrared sensors that detect nearby objects), gas sensors (e.g.,gas detection sensors to detection concentrations of hazardous gases forsafety or to measure pollutants in the atmosphere), or other componentsthat may provide indications, measurements, or signals corresponding toa surrounding physical environment.

With respect to cameras, the client device 102 may have a camera systemcomprising, for example, front cameras on a front surface of the clientdevice 102 and rear cameras on a rear surface of the client device 102.The front cameras may, for example, be used to capture still images andvideo of a user of the client device 102 (e.g., “selfies”), which maythen be augmented with augmentation data (e.g., filters) describedabove. The rear cameras may, for example, be used to capture stillimages and videos in a more traditional camera mode, with these imagessimilarly being augmented with augmentation data. In addition to frontand rear cameras, the client device 102 may also include a 360° camerafor capturing 360° photographs and videos.

Further, the camera system of a client device 102 may include dual rearcameras (e.g., a primary camera as well as a depth-sensing camera), oreven triple, quad, or penta rear camera configurations on the front andrear sides of the client device 102. These multiple cameras systems mayinclude a wide camera, an ultra-wide camera, a telephoto camera, a macrocamera, and a depth sensor, for example.

The position components 1034 include location sensor components (e.g., aGPS receiver component), altitude sensor components (e.g., altimeters orbarometers that detect air pressure from which altitude may be derived),orientation sensor components (e.g., magnetometers), and the like.

Communication may be implemented using a wide variety of technologies.The I/O components 1038 further include communication components 1036operable to couple the machine 1000 to a network 1020 or devices 1022via respective coupling or connections. For example, the communicationcomponents 1036 may include a network interface component or anothersuitable device to interface with the network 1020. In further examples,the communication components 1036 may include wired communicationcomponents, wireless communication components, cellular communicationcomponents, Near Field Communication (NFC) components, Bluetooth®components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and othercommunication components to provide communication via other modalities.The devices 1022 may be another machine or any of a wide variety ofperipheral devices (e.g., a peripheral device coupled via a USB).

Moreover, the communication components 1036 may detect identifiers orinclude components operable to detect identifiers. For example, thecommunication components 1036 may include Radio Frequency Identification(RFID) tag reader components, NFC smart tag detection components,optical reader components (e.g., an optical sensor to detectone-dimensional bar codes such as Universal Product Code (UPC) bar code,multi-dimensional bar codes such as Quick Response (QR) code, Azteccode, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, UCC RSS-2Dbar code, and other optical codes), or acoustic detection components(e.g., microphones to identify tagged audio signals). In addition, avariety of information may be derived via the communication components1036, such as location via Internet Protocol (IP) geolocation, locationvia Wi-Fi® signal triangulation, location via detecting an NFC beaconsignal that may indicate a particular location, and so forth.

The various memories (e.g., main memory 1012, static memory 1014, andmemory of the processors 1002) and storage unit 1016 may store one ormore sets of instructions and data structures (e.g., software) embodyingor used by any one or more of the methodologies or functions describedherein. These instructions (e.g., the instructions 1008), when executedby processors 1002, cause various operations to implement the disclosedexamples.

The instructions 1008 may be transmitted or received over the network1020, using a transmission medium, via a network interface device (e.g.,a network interface component included in the communication components1036) and using any one of several well-known transfer protocols (e.g.,hypertext transfer protocol (HTTP)). Similarly, the instructions 1008may be transmitted or received using a transmission medium via acoupling (e.g., a peer-to-peer coupling) to the devices 1022.

Software Architecture

FIG. 1 is a block diagram 1100 illustrating a software architecture1104, which can be installed on any one or more of the devices describedherein. The software architecture 1104 is supported by hardware such asa machine 1102 that includes processors 1120, memory 1126, and I/Ocomponents 1138. In this example, the software architecture 1104 can beconceptualized as a stack of layers, where each layer provides aparticular functionality. The software architecture 1104 includes layerssuch as an operating system 1112, libraries 1110, frameworks 1108, andapplications 1106. Operationally, the applications 1106 invoke API calls1150 through the software stack and receive messages 1152 in response tothe API calls 1150.

The operating system 1112 manages hardware resources and provides commonservices. The operating system 1112 includes, for example, a kernel1114, services 1116, and drivers 1122. The kernel 1114 acts as anabstraction layer between the hardware and the other software layers.For example, the kernel 1114 provides memory management, processormanagement (e.g., scheduling), component management, networking, andsecurity settings, among other functionalities. The services 1116 canprovide other common services for the other software layers. The drivers1122 are responsible for controlling or interfacing with the underlyinghardware. For instance, the drivers 1122 can include display drivers,camera drivers, BLUETOOTH® or BLUETOOTH® Low Energy drivers, flashmemory drivers, serial communication drivers (e.g., USB drivers), WI-FI®drivers, audio drivers, power management drivers, and so forth.

The libraries 1110 provide a common low-level infrastructure used byapplications 1106. The libraries 1110 can include system libraries 1118(e.g., C standard library) that provide functions such as memoryallocation functions, string manipulation functions, mathematicfunctions, and the like. In addition, the libraries 1110 can include APIlibraries 1124 such as media libraries (e.g., libraries to supportpresentation and manipulation of various media formats such as MovingPicture Experts Group-4 (MPEG4), Advanced Video Coding (H.264 or AVC),Moving Picture Experts Group Layer-3 (MP3), Advanced Audio Coding (AAC),Adaptive Multi-Rate (AMR) audio codec, Joint Photographic Experts Group(JPEG or JPG), or Portable Network Graphics (PNG)), graphics libraries(e.g., an OpenGL framework used to render in 2D and 3D in a graphiccontent on a display), database libraries (e.g., SQLite to providevarious relational database functions), web libraries (e.g., WebKit toprovide web browsing functionality), and the like. The libraries 1110can also include a wide variety of other libraries 1128 to provide manyother APIs to the applications 1106.

The frameworks 1108 provide a common high-level infrastructure that isused by the applications 1106. For example, the frameworks 1108 providevarious graphical user interface functions, high-level resourcemanagement, and high-level location services. The frameworks 1108 canprovide a broad spectrum of other APIs that can be used by theapplications 1106, some of which may be specific to a particularoperating system or platform.

In an example, the applications 1106 may include a home application1136, a contacts application 1130, a browser application 1132, a bookreader application 1134, a location application 1142, a mediaapplication 1144, a messaging application 1146, a game application 1148,and a broad assortment of other applications such as an externalapplication 1140. The applications 1106 are programs that executefunctions defined in the programs. Various programming languages can beemployed to create one or more of the applications 1106, structured in avariety of manners, such as object-oriented programming languages (e.g.,Objective-C, Java, or C++) or procedural programming languages (e.g., Cor assembly language). In a specific example, the external application1140 (e.g., an application developed using the ANDROID™ or IOS™ SDK byan entity other than the vendor of the particular platform) may bemobile software running on a mobile operating system such as IOS™,ANDROID™, WINDOWS® Phone, or another mobile operating system. In thisexample, the external application 1140 can invoke the API calls 1150provided by the operating system 1112 to facilitate functionalitydescribed herein.

Glossary

“Carrier signal” refers to any intangible medium that is capable ofstoring, encoding, or carrying instructions for execution by themachine, and includes digital or analog communications signals or otherintangible media to facilitate communication of such instructions.Instructions may be transmitted or received over a network using atransmission medium via a network interface device.

“Client device” refers to any machine that interfaces to acommunications network to obtain resources from one or more serversystems or other client devices. A client device may be, but is notlimited to, a mobile phone, desktop computer, laptop, portable digitalassistant (PDA), smartphone, tablet, ultrabook, netbook, laptop,multi-processor system, microprocessor-based or programmable consumerelectronics, game console, set-top box, or any other communicationdevice that a user may use to access a network.

“Communication network” refers to one or more portions of a network thatmay be an ad hoc network, an intranet, an extranet, a virtual privatenetwork (VPN), a local area network (LAN), a wireless LAN (WLAN), a widearea network (WAN), a wireless WAN (WWAN), a metropolitan area network(MAN), the Internet, a portion of the Internet, a portion of the PublicSwitched Telephone Network (PSTN), a plain old telephone service (POTS)network, a cellular telephone network, a wireless network, a Wi-Fi®network, another type of network, or a combination of two or more suchnetworks. For example, a network or a portion of a network may include awireless or cellular network and the coupling may be a Code DivisionMultiple Access (CDMA) connection, a Global System for Mobilecommunications (GSM) connection, or other types of cellular or wirelesscoupling. In this example, the coupling may implement any of a varietyof types of data transfer technology, such as Single Carrier RadioTransmission Technology (1×RTT), Evolution-Data Optimized (EVDO)technology, General Packet Radio Service (GPRS) technology, EnhancedData rates for GSM Evolution (EDGE) technology, third GenerationPartnership Project (3GPP) including 3G, fourth generation wireless (4G)networks, Universal Mobile Telecommunications System (UMTS), High SpeedPacket Access (HSPA), Worldwide Interoperability for Microwave Access(WiMAX), Long Term Evolution (LTE) standard, others defined by variousstandard-setting organizations, other long-range protocols, or otherdata transfer technology.

“Component” refers to a device, physical entity, or logic havingboundaries defined by function or subroutine calls, branch points, APIs,or other technologies that provide for the partitioning ormodularization of particular processing or control functions. Componentsmay be combined via their interfaces with other components to carry outa machine process. A component may be a packaged functional hardwareunit designed for use with other components and a part of a program thatusually performs a particular function of related functions.

Components may constitute either software components (e.g., codeembodied on a machine-readable medium) or hardware components. A“hardware component” is a tangible unit capable of performing certainoperations and may be configured or arranged in a certain physicalmanner. In various examples, one or more computer systems (e.g., astandalone computer system, a client computer system, or a servercomputer system) or one or more hardware components of a computer system(e.g., a processor or a group of processors) may be configured bysoftware (e.g., an application or application portion) as a hardwarecomponent that operates to perform certain operations as describedherein.

A hardware component may also be implemented mechanically,electronically, or any suitable combination thereof. For example, ahardware component may include dedicated circuitry or logic that ispermanently configured to perform certain operations. A hardwarecomponent may be a special-purpose processor, such as afield-programmable gate array (FPGA) or an application specificintegrated circuit (ASIC). A hardware component may also includeprogrammable logic or circuitry that is temporarily configured bysoftware to perform certain operations. For example, a hardwarecomponent may include software executed by a general-purpose processoror other programmable processor. Once configured by such software,hardware components become specific machines (or specific components ofa machine) uniquely tailored to perform the configured functions and areno longer general-purpose processors. It will be appreciated that thedecision to implement a hardware component mechanically, in dedicatedand permanently configured circuitry, or in temporarily configuredcircuitry (e.g., configured by software), may be driven by cost and timeconsiderations. Accordingly, the phrase “hardware component” (or“hardware-implemented component”) should be understood to encompass atangible entity, be that an entity that is physically constructed,permanently configured (e.g., hardwired), or temporarily configured(e.g., programmed) to operate in a certain manner or to perform certainoperations described herein.

Considering examples in which hardware components are temporarilyconfigured (e.g., programmed), each of the hardware components need notbe configured or instantiated at any one instance in time. For example,where a hardware component comprises a general-purpose processorconfigured by software to become a special-purpose processor, thegeneral-purpose processor may be configured as respectively differentspecial-purpose processors (e.g., comprising different hardwarecomponents) at different times. Software accordingly configures aparticular processor or processors, for example, to constitute aparticular hardware component at one instance of time and to constitutea different hardware component at a different instance of time.

Hardware components can provide information to, and receive informationfrom, other hardware components. Accordingly, the described hardwarecomponents may be regarded as being communicatively coupled. Wheremultiple hardware components exist contemporaneously, communications maybe achieved through signal transmission (e.g., over appropriate circuitsand buses) between or among two or more of the hardware components. Inexamples in which multiple hardware components are configured orinstantiated at different times, communications between such hardwarecomponents may be achieved, for example, through the storage andretrieval of information in memory structures to which the multiplehardware components have access. For example, one hardware component mayperform an operation and store the output of that operation in a memorydevice to which it is communicatively coupled. A further hardwarecomponent may then, at a later time, access the memory device toretrieve and process the stored output. Hardware components may alsoinitiate communications with input or output devices, and can operate ona resource (e.g., a collection of information).

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implementedcomponents that operate to perform one or more operations or functionsdescribed herein. As used herein, “processor-implemented component”refers to a hardware component implemented using one or more processors.Similarly, the methods described herein may be at least partiallyprocessor-implemented, with a particular processor or processors beingan example of hardware. For example, at least some of the operations ofa method may be performed by one or more processors 1002 orprocessor-implemented components. Moreover, the one or more processorsmay also operate to support performance of the relevant operations in a“cloud computing” environment or as a “software as a service” (SaaS).For example, at least some of the operations may be performed by a groupof computers (as examples of machines including processors), with theseoperations being accessible via a network (e.g., the Internet) and viaone or more appropriate interfaces (e.g., an API). The performance ofcertain of the operations may be distributed among the processors, notonly residing within a single machine, but deployed across a number ofmachines. In some examples, the processors or processor-implementedcomponents may be located in a single geographic location (e.g., withina home environment, an office environment, or a server farm). In otherexamples, the processors or processor-implemented components may bedistributed across a number of geographic locations.

“Computer-readable storage medium” refers to both machine-storage mediaand transmission media. Thus, the terms include both storagedevices/media and carrier waves/modulated data signals. The terms“machine-readable medium,” “computer-readable medium,” and“device-readable medium” mean the same thing and may be usedinterchangeably in this disclosure.

“Ephemeral message” refers to a message that is accessible for atime-limited duration. An ephemeral message may be a text, an image, avideo and the like. The access time for the ephemeral message may be setby the message sender. Alternatively, the access time may be a defaultsetting or a setting specified by the recipient. Regardless of thesetting technique, the message is transitory.

“Machine storage medium” refers to a single or multiple storage devicesand media (e.g., a centralized or distributed database, and associatedcaches and servers) that store executable instructions, routines anddata. The term shall accordingly be taken to include, but not be limitedto, solid-state memories, and optical and magnetic media, includingmemory internal or external to processors. Specific examples ofmachine-storage media, computer-storage media and device-storage mediainclude non-volatile memory, including by way of example semiconductormemory devices, e.g., erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), FPGA, andflash memory devices; magnetic disks such as internal hard disks andremovable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks Theterms “machine-storage medium,” “device-storage medium,”“computer-storage medium” mean the same thing and may be usedinterchangeably in this disclosure. The terms “machine-storage media,”“computer-storage media,” and “device-storage media” specificallyexclude carrier waves, modulated data signals, and other such media, atleast some of which are covered under the term “signal medium.”

“Non-transitory computer-readable storage medium” refers to a tangiblemedium that is capable of storing, encoding, or carrying theinstructions for execution by a machine.

“Signal medium” refers to any intangible medium that is capable ofstoring, encoding, or carrying the instructions for execution by amachine and includes digital or analog communications signals or otherintangible media to facilitate communication of software or data. Theterm “signal medium” shall be taken to include any form of a modulateddata signal, carrier wave, and so forth. The term “modulated datasignal” means a signal that has one or more of its characteristics setor changed in such a matter as to encode information in the signal. Theterms “transmission medium” and “signal medium” mean the same thing andmay be used interchangeably in this disclosure.

Changes and modifications may be made to the disclosed examples withoutdeparting from the scope of the present disclosure. These and otherchanges or modifications are intended to be included within the scope ofthe present disclosure, as expressed in the following claims.

What is claimed is:
 1. A method comprising: receiving, by one or moreprocessors of a client device, a video that includes a depiction of areal-world object; generating, by the one or more processors, athree-dimensional (3D) body mesh associated with the real-world objectthat tracks movement of the real-world object across frames of thevideo; determining UV positions of the real-world object depicted in thevideo to obtain pixel values associated with the UV positions;generating an external mesh and associated augmented reality (AR)element representing the real-world object based on the pixel valuesassociated with the UV positions; deforming the external mesh based onchanges to the 3D body mesh and a deformation parameter; and modifyingthe video to replace the real-world object with the AR element based onthe deformed external mesh.
 2. The method of claim 1, wherein thereal-world object comprises a person; and wherein the AR elementcomprises a texture that represents visual attributes of the body of theperson.
 3. The method of claim 1, further comprising automaticallyestablishing a correspondence between the 3D body mesh associated withthe real-world object and the external mesh, wherein the correspondencecomprises placing the external mesh at a same position and orientationas the 3D body mesh.
 4. The method of claim 1, wherein the UV positionsrepresent a texture of the real-world object in a two-dimensional (2D)space.
 5. The method of claim 1, wherein the video is modified in realtime to depict the real-world object being changed into the AR elementwhile the real-world object moves around a depicted real-worldenvironment.
 6. The method of claim 1, wherein the real-world object isreplaced with the AR element according to a blending parameter thatcomprises a linear function or a non-linear function.
 7. The method ofclaim 1, further comprising obtaining placement information for theexternal mesh that describes where to position the external meshrelative to the 3D body mesh.
 8. The method of claim 1, furthercomprising: computing a change in body shape, body state, or bodyproperties of the real-world object across the frames of the video; andadjusting a shape of the external mesh based on the change in the shape,body state, or body properties.
 9. The method of claim 1, furthercomprising: computing a change in position or scale of the real-worldobject across the frames of the video; and adjusting a position or scaleof the external mesh based on the change in the position or scale. 10.The method of claim 1, further comprising: computing a change inrotation of the real-world object across the frames of the video; androtating the external mesh in 3D based on the change in the rotation.11. The method of claim 1, further comprising: determining a first setof coordinates of the body mesh in a normal-tangent space for a firstframe of the frames of the video; determining a second set ofcoordinates of the body mesh in the normal-tangent space for a secondframe of the frames of the video; computing, in real time, a changebetween the first and second sets of coordinates in the normal-tangentspace; and transferring the change between the first and second sets ofcoordinates in the normal-tangent space to the external mesh.
 12. Themethod of claim 1, further comprising: receiving, by a messagingapplication, placement information for the external mesh from athird-party designer of the external mesh; and adding the external meshto the body mesh based on the placement information.
 13. The method ofclaim 1, further comprising: generating a two-dimensional (2D) texturemap of a frame of the video; identifying a portion of the 2D texture mapcorresponding to the real-world object; and determining the UV positionsof the real-world object depicted in the video to obtain pixel valuesassociated with the UV positions based on the portion of the 2D texturemap corresponding to the real-world object.
 14. The method of claim 1,wherein the deformation parameter identifies a portion of the externalmesh and includes a modification to the portion of the external mesh.15. The method of claim 14, wherein the modification includes enlarginga size of the portion of the external mesh to generate an enlargedportion of the external mesh.
 16. The method of claim 15, furthercomprising: determining pixel values of the AR element corresponding toan edge of the portion of the external mesh being enlarged; and blendingthe pixel values associated with the AR element from the edge of theportion of the external mesh into a portion of the AR elementcorresponding to the enlarged portion of the external mesh.
 17. Themethod of claim 14, wherein the modification includes reducing a size ofthe portion of the external mesh.
 18. The method of claim 14, whereinthe modification comprises a change to a color of the portion of theexternal mesh, further comprising adjusting pixel values of the ARelement corresponding to the portion of the external mesh based on thechange to the color.
 19. A system comprising: a processor of a clientdevice; and a memory component having instructions stored thereon that,when executed by the processor, cause the processor to performoperations comprising: receiving a video that includes a depiction of areal-world object; generating a three-dimensional (3D) body meshassociated with the real-world object that tracks movement of thereal-world object across frames of the video; determining UV positionsof the real-world object depicted in the video to obtain pixel valuesassociated with the UV positions; generating an external mesh andassociated augmented reality (AR) element representing the real-worldobject based on the pixel values associated with the UV positions;deforming the external mesh based on changes to the 3D body mesh and adeformation parameter; and modifying the video to replace the real-worldobject with the AR element based on the deformed external mesh.
 20. Anon-transitory computer-readable storage medium having stored thereoninstructions that, when executed by a processor of a client device,cause the processor to perform operations comprising: receiving a videothat includes a depiction of a real-world object; generating athree-dimensional (3D) body mesh associated with the real-world objectthat tracks movement of the real-world object across frames of thevideo; determining UV positions of the real-world object depicted in thevideo to obtain pixel values associated with the UV positions;generating an external mesh and associated augmented reality (AR)element representing the real-world object based on the pixel valuesassociated with the UV positions; deforming the external mesh based onchanges to the 3D body mesh and a deformation parameter; and modifyingthe video to replace the real-world object with the AR element based onthe deformed external mesh.